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251 Cards in this Set
- Front
- Back
Big Bang was when?
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15 billion years ago
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One second after Big Bang?
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All matter formed
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Protons are:
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positively charged, part of nucleus
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Neutrons are:
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no charge, part of nucleus
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Electrons are:
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negative charge, in orbit
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Do all atoms have all three parts?
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NO
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300,000 years after Big Bang?
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Protons, Neutrons, and Electrons came together to form Hydrogen and Helium atoms
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What is Hydrogen made of?
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1 proton, 1 electron
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Helium is made of?
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2 protons, 2 neutrons, 2 electrons
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one billion years after Big Bang?
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Hydrogen and Helium atoms clump together to make Galaxies and Stars
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When the Sun formed
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5 billion years ago
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How hot the Sun is at core
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28 million degrees Fahrenheit
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How hot Sun is at surface
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11,000 degrees Fahrenheit
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Sun gets energy from
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turning Hydrogen into Helium through Nuclear Fission
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Two most abundant elements in Sun and universe
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Hydrogen and helium
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Earth formed when:
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4.6 billion years ago
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General Characteristics of Earth
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1) Hot interior, 2) Magnetic Field and atmosphere, 3) liquid, water, and ice vapor
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Where earth gets its interior heat
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Radioactive decay of elements in Earth's mantle
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Moon formed when:
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between 4.6 and 4 billion years ago
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Moon formed how?
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Mars sized planet slammed into Earth
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General Characteristics of moon (4)
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1) No atmosphere or magnetic field, 2) cold interior, 3) some ice at poles, 4) Same side always faces the Earth (orbit = rotation)
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Moon's main affect on Earth
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Creates tides (what side moon is in comparison to Sun)
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Where Earth's atmosphere came from
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Gases released when the Earth's mantle was compressed into four distinct layers (crust, mantle, outer core, inner core
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Make up of Earth's early atmosphere
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Lots of Carbon Dioxide
Very little free Oxygen |
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Make up of Earth's atmosphere now
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very little carbon dioxide
lots of oxygen |
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Increase in oxygen gas caused by?
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Evolution of Photosynthesis
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Decrease in CO2 caused by?
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CO2 being tied up in living and dead organisms (fossil fuels)
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Currently causing increase in CO2
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burning of fossil fuels releases carbon
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Layer of atmospheric gases that protects life on Earth
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Ozone
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Ozone protects earth from:
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Ultraviolet light (radiation)
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How is Ozone formed?
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Oxygen Gas (O)
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How high is Ozone?
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31 miles high
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How thick is ozone?
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a few millimeters
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Most important feature of earth
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Presence of liquid water.
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How much of Earth's surface is covered in water?
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75% of surface
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How much of Earth's water is salt water?
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97%
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How much of Earth's water is fresh water?
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3%
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How much fresh water is tied up in glaciers and ice caps?
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68.7%
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Origin of life on Earth when?
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about 3.5 billion years ago
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First life on Earth was
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Bacteria, Archaea
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Origin of Photosynthesis when?
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about 2.5 billion years ago (with oxygen)
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Origin of Eukaryotic Cells when?
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about 1-2 billion years ago
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First land Animals when?
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about 500 million years ago
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First land plants when?
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about 500 million years ago
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Atoms
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Fundamental substance that has mass and takes up space
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Molecule
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the name given to atoms that have an identical number of protons in their nucleus.
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Element
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defined by the number of Protons in its Nucleus (each has a unique number of protons in its nucleus)
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Atomic Number
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the number of protons in the nucleus
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Number of protons usually equal the number of
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electrons
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If protons and electrons are equal, the atom is:
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neutral
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Mass Number
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the total number of protons and neutrons
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do neutrons and protons have to be equal?
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NO
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isotope
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elements that have the same number of protons, but different number of neutrons
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isotope example:
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^12 C (6 protons, 6 neutrons)
^14 C (6 protons, 8 neutrons) ^14 C is an isotope of Carbon (C12) |
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Radioactive decay
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If an element has too many neutrons, it may be unstable and give off energy (radiation) as its nucleus decays into a more stable product
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^14 C is an unstable radioisotope that dcays (gives off energy) until it turns into
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Nitrogen, ^14 N
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Time it takes for half the sample to decay?
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half-life
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How do tracer studies work?
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attach Radioisotopes to molecules and track where they go
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Photosynthesis (equation)
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12H2O + 6CO2 --> 6O2 + C6H12O6 + 6H2O
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For Photosynthesis: If you use ^14C (in CO2) instead of 12C and find: 12H2O + 6^14CO2 --> 6O2 + ^14 C6H12O6 + 6H20
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Carbon atoms from CO2 are used to make the glucose molecule
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Electrons orbit the nucleus in successive energy levels called
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shells
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First shell holds
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2 electrons
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Second shell holds
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8 electrons
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If outer shell is not full, atom wants to
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gain, lose, or share electrons
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Chemical bonds
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outer shell well gain, lose, or share electrons
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Hydrogen (number in shell, is it chemically reactive?)
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one electron in outer shell, wants 2.
Is chemically reactive |
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Helium (number in shell, is it chemically reactive?)
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two electrons in outer shell, it's full.
not chemically reactive |
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Oxygen (number in shell, is it chemically reactive?)
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First shell full at 2 electrons
Second shell has 6 but wants 8 is chemically reactive |
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Carbon (number in shell, is it chemically reactive?)
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First shell is full, outer has 4, wants 8.
Can form 4 chemical bonds highly chemically reactive |
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What is the most important biological element and why?
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Carbon, can make 4 chemical bonds
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Carbon's atomic number?
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6
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Ion
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when an atom loses or gains an electron, it becomes positively or negatively charged.
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A negatively charged ion
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Anion
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A positively charged ion
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Cation
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Ionic bond
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when one atom gives up an electron that another accepts
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Weak bond
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electron attraction between opposite charged atoms
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covalent bond
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the strongest bond. when atoms share electrons to complete their outer shell
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Non-polar covalent bond
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two identical atoms share electrons equally and show no different in charge
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polar covalent bond
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two different atoms share electrons unequally, creating a positive side and a negative side
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Hydrogen bond
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when hydrogen atoms locked into polar covalent bonds stick to other atoms that are negatively charged
*relatively weak |
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Important Properties of Water:
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1) Water is a heat reservoir
2) Water is an excellent solvent 3) Water is sticky 4) Water evaporates 5) Ice is less dense than water |
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Water is a heat reservoir
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water absorbs a lot of heat before increasing in temperature
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Water is an excellent solvent
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things dissolve in water! because it's polar charges can keep other ions separated in solution
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Hydrophilic
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water-loving (Polar)
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Hydrophobic
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water-hating (Non-Polar)
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Water is sticky
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water sticks to itself and creates a surface tension
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Capillary action
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tendency of a liquid to rise in narrow tubes or to be drawn into small openings
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Water evaporates
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takes heat with it
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Ice is less dense than water
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it assumes a more uniform shape, this is why ice floats and expands
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Water molecules often split into ions of
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Hydrogen ion (H+) and Hydroxide Ion (OH-)
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What is the pH scale
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a measure of how many free H+ ions there are in a solution
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What is neutral pH?
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7.0 (H+ = OH)
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The greater the H+ concentration,
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the lower the pH, the more acidic the solution (pH < 7)
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The lower the (H+) concentration,
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the higher the pH, the more alkaline or basic the solution (pH > 7)
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pH value of most fluids in your body
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7.3 and 7.5, slightly basic
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Acid
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molecule that donates Hydrogen ions (H+) when dissolved in water
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Example of an acid:
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HCL (Hydrochloric acid) = splits into H+ and CL-
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Hypoventilation
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Breathing too shallow, CO2 levels increase, and blood is too acidic
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Respiratory Acidosis
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blood too acidic
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Bases
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molecules that accept free hydrogen ions (H+)
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Example of base
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milk of magnesia
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Hyperventilation
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breathing too rapidly, CO2 levels drop, blood becomes too basic
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Tetany
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Low levels of calcium cause muscles to remain contracted. can cause death
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Salts
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molecule that releases ions other than H+ when dissolved in water
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Why is Sea Salt bigger than Table Salt?
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...
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Functional groups
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single atoms or clusters of atoms covalently bonded to the carbon atom. Greatly influences the properties of the molecule
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Organic molecule
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contains carbon and at least one hydrogen atom
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Carbohydrates
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also called Sugars or Saccharides.
Polar, Hydrophilic and this are the most abundant class of biological molecules |
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Simple sugars
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also called monosaccharides (one sugar molecule)
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Glucose *
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C6H12O6. Your brain's preferred food.
Example of simple sugar |
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Short chain sugars
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also called disaccharides or Oligosaccharides.
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Examples of Short-chain sugars
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-sucrose (table sugar) - Glucose and Fructose is the most abundant sugar in nature
--Milk sugar (lactose) - glucose and galactose |
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long-chain sugars
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also called complex carbohydrates. chains of many sugar molecules
Most common types: Cellulose, Starch, Glycogen |
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Cellulose
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makes plant cell walls rigid (you cannot digest this)
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Starch
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how plants store the glucose they make
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Glycogen
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how animals store glucose they eat
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How are Simple Sugars, Short-chain sugars, and long-chain sugars similar and different?
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All are made of Glucose chains.
Differ in how the glucose molecules are linked together |
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Lipids
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fats and oils - greasy and oily, nonpolar and hydrophonic
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Fats and Fatty acids
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a very long chain of carbon atoms, a carboxyl group at one end and Hydrogen atoms at most or all of the remaining carbons
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*Saturated Fatty acid
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carbons are all joined by single bonds and are saturated with hydrogen atoms. Raises cholesterol levels
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*Unsaturated fatty acid
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there are double bonds between some of the carbon atoms. Lowers blood cholesterol levels
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Animal fats are ___ at room temperature
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solid
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Plant fats are ____ at room temperature
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liquid
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Triglycerides
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most abundant lipids in your body and the richest source of energy
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Where to vertebrates store triglycerides (fat)?
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as tiny droplets inside fat cells of adipose tissue
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Why do you store triglycerides (far) and not sugar?
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Fats have twice as much energy as sugars
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Phospholipids
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a main component of plant and animal cell membranes. Two nonpolar, hydrophobic fatty acid tails, and a hydrophilic polar head. The heads face away form each other, the tails are in the middle. Because the middle layer repels water, the cell membrane is waterproof
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Waxes
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long-chain fatty acids linked to long-chain alcohols or carbon rings. All repel water. Found in skin and hair, plant cuticles, beeswax, feather waterproofing in birds.
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Sterols
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do not contain fatty acids. all have four fused-together carbon rings
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Cholesterol
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can be remodeled into many important biological molecules such as bile, salts, steroids, Estrogen, and Testosterone.
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Example of Sterols
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cholesterol
|
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How do we make Vitamin D?
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in our skin, sunlight (UVB) converts one kind of cholesterol into it
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molecules of life
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1) Carbohydrates, 2) Lipids, 3) Nucleotides, 4) Proteins
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Nucleotides
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have on sugar, at least one phosphate group, and one nitrogen-containing base
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DNA and RNA are made from
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nucleotides A, G, C, T
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ATP
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body's source of energy
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Proteins
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made from amino acids
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Amino acids
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a carbon atom that has an amine group, a carboxyl group, a hydrogen atom, and one or more atoms called the R group
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a string of animo acids is called a
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polypeptide chain/proteins
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how old are the oldest known fossils
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3.5 billion years old
|
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oldest fossils are most like
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cyanobacteria
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Properties of Life
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1) Capacity for Metabolism
2) Controlled responses to the environment 3) Growth 4) Self-reproduction |
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Metabolism
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controlled chemical reactions that acquire and use energy
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Three structural features that all cells share
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1) Plasma or Cell Membrane
2) DNA, RNA, and Ribosomes 3) Cytoplasm |
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Main component of Plasma membrane
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phospholipids
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describe the phospholipids
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1 Hydrophilic head on one end
2 Hydrophobic tails on other |
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describe cell membrane
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phospholipid bilayer - 2 layers of lipids
hydrophilic heads on outside hydrophobic tails face inside |
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DNA
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instructions for making proteins
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RNA and Ribosomes
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the molecules that rad DNA and make proteins
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why is DNA a better genetic material than RNA
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DNA: double stranded, twisted, and stable
RNA: single stranded, easily broken |
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Cytoplasm
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water based 'juice' inside the cell
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Prokaryotic cells
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simplest and smallest cells
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2/3 Domains of Prokaryotic cells
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Bacteria and Archaea
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Archaea
|
-DNA kept in a Nucleoid region with no membrane around it
-DNA is circular, not linear like your chromosomes -Have plasmids |
|
Plasmids
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small circles of DNA that can be shared with other bacteria
|
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Endosymbiosis
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third domain, eukarya, formed from symbiosis between Bacteria and Archaea
|
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Steps in Endosymbiosis
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1) 1-2 billion years ago, Archaea cell engulfed Bacterial cell that evolved into Mitochondrion
2) After step 1, a second Bacterial cell is engulfed that evolved into the Chloroplast |
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Evidence for a Symbiotic Bacterial origin of Mitochondria and Chloroplasts
|
Mitochondria and Chloroplasts have
1) their own DNA, RNA, and Ribosomes 2) The genetic code of bacteria 3) Circular DNA like bacteria |
|
Eukaryotic cells
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more complex and larger than prokaryotes
1) single celled or multicellular 2) DNA in a Nucleus (with a membrane) 3) DNA is linear (not circular) 4) Endomembrane system, Organelles, and cytoskeleton |
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colonial
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live singular
|
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multicellular
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depend on others
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Nucleus
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membrane that surrounds Eukaryotic DNA
|
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Nuclear membrane made from
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double phospholipid bilayer
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why is DNA kept in the nucleus?
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prevent DNA from being damaged by chemical reactions in cytoplasm
|
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nucleolus
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region inside nucleus where Ribosomes are made; no membrane around it
|
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Endomembrane system
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flattened sacs inside cytoplasm
|
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Endoplasmic Reticulum (ER)
|
assembles proteins and lipids in cytoplasm
|
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Golgi Bodies
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transport things out of cell
|
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vesicles
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sacs that bud off ER, Golgi bodies, or plasma membrane
|
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lysosomes
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Digest things inside cell
|
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Peroxisomes
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site of alcohol detoxification in liver cells. also breakdown hydrogen. peroxide by enzyme catalase.
|
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vacuoles
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fluid-filled sacs store food or water in cell
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cytoskeleton
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protein filaments that give eukaryotic cells shape, internal structure, help move the cell, and move things around inside the cell
|
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microtubules
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move chromosomes during cell division
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kinesins
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move chloroplasts in plant's leaves as an angle of sun changes
|
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flagella
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usually one or a few on one end of cell. Movement
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cilia
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usually many tiny ones all over cell. movement.
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energy
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capacity to do work
|
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1st Law of Thermodynamics
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Energy can be converted from one form to another, but cannot be created or destroyed
|
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2nd Law of Thermodynamics
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Entropy or disorder increases unless energy is supplied to maintain order
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What is Life's main energy source
|
sunlight
|
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What is Life's main energy carrying molecule
|
ATP (adenosine Tri-phosphate)
|
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how does ATP transfer energy
|
it gives up its third phosphate group to become ADP
|
|
a chemical reaction that involves the transfer of a phosphate group
|
phosphorylation
|
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Redox Reactions
|
Oxidation-reduction reactions. Electrons are transferred from one molecule to another
|
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a molecule is oxidized if
|
it gives up electrons
|
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a molecule is reduced if
|
it gains electrons
|
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electron transport chains
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enzymes or other molecules that accept and give up electrons in sequence
-electrons give up a little bit of energy every step of the way |
|
metabolic pathways
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enzyme-controlled sequences of chemical reactions in cells
|
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anabolic (biosynthetic) pathways
|
require inputs of energy. Construct high-energy molecules from smaller molecules (ie: assembly of glucose, starch, and glycogen)
|
|
most important anabolic pathway
|
photosynthesis
|
|
catabolic (degradative) pathway
|
release energy. break down molecules into smaller, low-energy products. breaking down glucose or fats to release their energy
|
|
most important catabolic pathway
|
cellular respiration
|
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enzymes are made from
|
proteins
|
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substrate
|
name for molecules that bind to enzyme
*shape is important. Either fits or doesn't |
|
active site
|
location on enzyme where substrate will bind
|
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activation energy
|
the energy need to start a chemical reaction
|
|
how do enzymes work
|
lower the activation energy needed to start a chemical reaction
|
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why are enzymes such important biological molecules
|
1) make chemical reactions happen hundreds or millions of times faster. 2) most can be reused. 3) lower activation energy.
|
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Control over Enzymes
|
1) cofactors, 2) environmental factors, 3) allosteric activation or inhibitions, 4) feedback inhibition
|
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Control over Enzymes: Co factors
|
help the enzyme function properly (are usually destroyed by the reaction and must be remade. Co-enzynes move electrons and hydrogen ions from one reaction to another
|
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Control over Enzymes: Environmental Factors
|
temperature, pH, and salt concentration must be key within very specific limits for most enzymes to function properly or optimally
|
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Control over Enzymes: Allosteric activation or inhibitions
|
another molecule called an allosteric inhibitor or activator can bind to the enzyme, change its shape, and either block or allow the enzyme to bind to the substrate
|
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Control over Enzymes: feedback inhibition
|
when a reaction product becomes too common, it blocks the enzyme from making more of the product
|
|
diffusion
|
solute tends to move from a region of high concentration to a region of low concentration
|
|
osmosis
|
diffusion of water from a region of high concentration to a region of low concentration
|
|
solution
|
a liquid
|
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solute
|
stuff dissolved in a liquid
|
|
in diffusion, what wants to move?
|
solute
|
|
in osmosis, what wants to move?
|
solution
|
|
what drives the movement of molecules in diffusion and osmosis
|
temperature (thermal energy)
-molecules move more with heat -temperature is measure of how fast molecules are moving |
|
What controls diffusion rates?
|
1) steeper concentration gradient = faster diffusion
2) smaller solutes diffuse faster than bigger solutes 3) higher temperature = faster diffusion |
|
What can cross the cell membrane?
|
hydrophobic molecules: O2, CO2, and other small, nonpolar molecules
|
|
What cannot cross the cell membrane?
|
Hydrophilic molecules: glucose, ions, and other large, polar molecules
|
|
transport proteins
|
passive transport, active transport
|
|
passive transport
|
does not require energy. movement with concentration gradient
|
|
active transport
|
does require energy. movement against concentration gradient.
|
|
transport vesicles
|
exocytosis and endocytosis
|
|
exocytosis
|
moving something out of the cell
|
|
endocytosis
|
moving something from outside to inside the cell
|
|
phagocytosis
|
cell eating
|
|
Overview of Photosynthesis
|
12H2O (water) + 6O2 (carbon dioxide) --> (enzymes) (light energy) C6H12O6 (Glucose) + 6O2 (oxygen) + 6H2O (water)
|
|
light
|
packets of electromagnetic energy called photons
|
|
relationship between Wavelength and Energy Level?
|
shorter wave lengths, highest energy.
longer wavelengths, lowest energy. |
|
pigment molecule
|
a molecule that can absorb light energy
|
|
most abundant plant pigment
|
chlorophyll
|
|
which wavelengths of light does chlorophyll absorb
|
blue and red
|
|
which wavelengths of light does chlorophyll reflect
|
green
|
|
accessory pigments
|
help capture other wavelengths of light
|
|
carotenes
|
reflect red and orange (carrots and flowers)
|
|
xanthophylls
|
reflect yellow, brown, purple (corn kernals)
|
|
why do the leaves of deciduous trees turn different colors in Autumn
|
plants stop manufacturing chlorophyll, so it disappears from leaves, and what's left behind is accessory pigments
|
|
photosystem
|
ring of pigment molecules surrounding a reaction center
|
|
how does photosystem work
|
light comes in, bounces around pigment molecules until it gets to reaction center
|
|
how do pigment molecules absorb light nergy?
|
by exciting electrons, giving more energy, and electrons jump to next highest energy shell
|
|
an excited electron can:
|
1) drop down to original shell and give off heat (hot sidewalk) 2) drop down, give off fluorescent light 3) be captured by another molecule (pheophytin)
|
|
Summary of Dark Reactions*
|
-Use ATP energy from light reactions
-Use hydrogen and electrons from NADPH and Carbon and Oxygen from carbon dioxide in air to make sugar molecules, C6H12O6 |
|
Enzyme that starts Dark Reaction
(most abundant protein on earth) |
Rubisco
|
|
Light Reaction: Step 1
What happens when p680 molecule receives a photon of light? |
it is oxidized and gives electrons to a pheophytin molecule
|
|
Light Reaction: Step 2
What does the Cytochrome Complex do? |
pumps H+ ions from the stroma into the Lumen creating a H+ concentration gradient (Active Transport)
|
|
Light Reactions: Step 3
What does p700 molecule do? |
accepts used electrons. Uses light energy to excite two more electrons
|
|
Light Reactions: Step 4
What does NADP+ Reductase do? |
Enzyme reduces NADP+, adds a H+ ion, and converts NADP+ into NADPH. NADP+ is the 'final electron acceptor'
|
|
what does NADPH do?
|
carries electrons and H+ ions to the Dark Reactions
|
|
Light Reactions: Step 5
What does ATP Synthase do? |
enzyme that phosphorylates ADP into ATP as H+ ions pass throuhg it
|
|
*Primary job of ATP
|
to carry energy
|
|
What drives the movement of H+ ions through ATP Synthase?
|
passive difussion of H+ ions due to the concentration gradient and... thermal energy!
|
|
Light Reaction: Step 6
How does the p680 molecule replace its lost electrons? |
two water molecules are split into electrons, hydrogren ions, and oxygen has.
2 H2O --> 4e- + O2 + 4H+ |
|
What happen to the electrons in Step 6 of Light Reaction?
|
electrons go to p680
|
|
What happen to the Hydrogen Ions in Step 6 of Light Reaction?
|
pass through ATP Synthase to make more ATP
|
|
What happens to the Oxygen in Step 6 of Light Reaction?
|
released into the atmospherel
|
|
does the action of the Cytochrome complex increase or decrease acidity in the Lumen?
|
increase acidity
|