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112 Cards in this Set
- Front
- Back
why is a hydroxide ion negatively charged?
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bc it has gained an electron from the hydrogen atom
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pure water contains _____ concentrations of hydrogen ions and hyrodixde ions.
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equal
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if the concentration of H+ exceeds the concentration of OH-, the solution is _____
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acidic
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a substance that releases hydrogen ions when it is dissolved in water.
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acid
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what happens when HCl is added to pure water?
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almost all of the HCl molecules separate into H+ and Cl-.
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A substance that combines with hydrogen ions, reducing their number.
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base
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the degree of acidity is expressed on the _____.
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ph scale
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what is neutrality on the ph scale?
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7, equal numbers of H+ and OH-
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acids have a ph ____ 7.
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below
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bases have a ph ____7.
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above
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small increases or decreases in ph may cause....
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drastic changes in both the structure and function of biological molecules, leading to the death of cells or entire organisms.
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compound that tends to maintain a solution at a constant ph by accepting or releasing H+ in response to small changes in H+ concentration.
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buffer
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what happens if blood becomes too acidic?
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bicarbonate accepts H+ to form carbonic acid
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what happens if blood becomes too basic?
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carbonic acid liberates hydrogen ions, which combine w/ the excess hydroxide ions, forming water.
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why are subfreezing temp. within the body usually lethal?
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spearlike ice crystles can rupture cells
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temperature reflects the speed of what?
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molecules
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the ____ the temperature, the ____ the molecule's average speed.
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higher, greater
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true/false
it requires more energy to heat water than it does to heat most other substances |
true
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the energy required to heat a gram of a substance by 1 celsius is called its....
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specific heat
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heat required to vaporize water is called...
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heat of vaporization
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true/false
ice is more dense than liquid water? |
false- ice is less dense
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what are the 3 domains of living organisms?
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1. bacteria
2. archaea 3. eukarya |
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no nucleus, small simple organisms, prokaryotic organisms
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bacteria
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extreme ophiles-->live in extreme conditions. single, simple cells
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archaea
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inside the cell is a nucleus, includes membrane organelles, much bigger than prokaryotic cells.
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eukarya
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what are the major subdivisions of eukarya?
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animalia, plantae, protists, and fungi
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use photosynthesis to make their own energy (plants)
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autotrophs
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eat organisms for energy (humans)
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heterotrophs
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the unifying theory of biology
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evolution
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the scientific theory derived from what..?
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observation and experiments
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what is the evolutionary process?
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1. genetic variation/ competition among variants
2. not all survive 3. adaptive characteristics inherited |
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a bacterial cell in the human body with a genetic variation that allows it to survive when the person takes antibiotics is an example of what..?
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natural selection
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parts of molecules, the basic structural unit of matter (the smallest pieces of stuff)
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atom
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positive charge
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proton
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negative charge
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electron
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no charge
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neutron
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an element is defined by the number of ____?
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protons
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the number of protons in a molecule tells us what?
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the atomic number
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what is the atomic mass?
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number of protons + number of neutrons
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what is the building up principle?
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electrons fill the shell closest to the nucleus, then begin to occupy the next shell
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how many electrons can the first shell hold?
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2
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how many electrons can the 2nd and 3rd shell fill?
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8
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ionic bonding is an attraction between...
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ions
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sodium has 1 electron in its outer shell, chlorine has 7, sodium can lose 1 electron to make chlorine's outershell full. what type of bonding is this?
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ionic
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makes up arthropod exoskeletons and fungus cell walls. polymer with glucose subunits and N-containing functional groups
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chitin
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what are lipids?
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1. fats, oils, and waxes
2. phospholipids 3. steroids |
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what are the 2 characterisitcs of lipids?
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1. large regions with mostly C and H; nonpolar
2. hydrophobic; insoluble in water |
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is the head of a phospholipid polar or non polar?
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polar
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is the tail of a phospholipid polar or non polar?
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non polar
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true/false
heads of phospholipids are hydrophobic? |
false- they are hydrophilic
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hydrophobic membrane core
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where 2 phospholipid tails meet (tails hate water, heads love water)
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what are phospholipids made of?
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1 glycerol, 2 fatty acids, and 1 polar group
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what hormones are steroids?
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estrogen and testosterone
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in a biological membrane, the phospholipds are arranged with the fatty acid chains facing the interior of the membrane. as a result, the interior of the membrane is....
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hydrophobic
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amino acid polymers
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protein
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proteins play many roles in cells...what are they?
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enzymes, hormones, structure, defense
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what are amino acids made of?
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1 amino group, 1 carboxyl group, 1 "R" group
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true/false
amino acids are molecular subunits of proteins |
true
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amino acids are joined by peptide bonds to form...?
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polypeptides
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different sequence of amino acids make...
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different proteins
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what are the levels of protein structure?
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primary: sequence
secondary: coiling tertiary: bending quarternary: 2 or more chains together |
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you have identified a protein that is unable to form disulfide bridges. this would affect which of the following?
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tertiary structure of protein
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nucleotide polymers that function in genetics and cell control
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nuceleic acids
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ATP is a..?
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energy carrier
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what are nucelotides made of?
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5 carbon sugar, phosphate, and N-containing base
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glucose is to starch as _____ is to _____.
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amino acid; protein
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what are 3 memrane functions?
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1. selectively isolates inside of the cell from the outside
2. regulates exchange of substances in and out of the cell 3. facilitates communication with other cells |
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what are the membrane proteins?
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1. transport proteins
2. recognition proteins |
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regulates movement through membrane
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transport proteins
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what are 3 types of transport proteins?
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1. channel proteins
2. carrier proteins 3. receptor proteins |
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proteins that punch a hole through membrane
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channel proteins
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trigger cellular response when specific molecules attach
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receptor proteins
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ID tags and attachment sites
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recognition proteins
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what is a type of recognition protein?
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glycoprotein
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movement down concentration gradient, no energy required
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passive transport
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water moves through differentially permeable membrane
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osmosis
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molecules move from area of high concentration to area of low concentration; down concentration gradient. after time concentrations become equal
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diffusion
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what are the 3 effects of osmosis?
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istonic, hypertonic, hypotonic
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"cell eating", cell englufs large particles
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phagocytosis
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"cell drinking", cell englufs extracellular fluid
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pinocytosis
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the cytoplasm of a certain cell, such as a neuron, already has a high concentration of K+ ions. How can K+ ions enter the cell?
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active transport
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strengthen attachment between cells and holds tissues together
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desmosomes
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prevent leakage between cells
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tight junctions
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cell to cell channels connecting adjacent cells. only in animals
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gap junctions
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channels through plant cell walls connecting adjacent cells
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plasmodesmata
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the electrical signal for a muscle to contract passes rapidly from one muscle cell to the next way of ____.
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gap junctions
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covalent bond
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when an atom with a partially full shell becomes stable by sharing electrons with another atom
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solutions that have a higher concentration of dissolved particles than does a cell's cytoplasm, and thus causes water to leave the cell by osmosis
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hypertonic
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concentration of water inside the cell is the same as concentration on the outside of cell, so there is no tendency for water to enter or leave the cell
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isotonic
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solutions that have a lower concentration of dissolved particles than a cell's cytoplasm, and thus cause water to enter the cell by osmosis
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hypotonic
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what happens when red blood cells are put into pure water (hypotonic solution)?
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they will swell and eventually burst
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what happens when red blood cells are put into a hypertonic solution?
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cells will shrivel up until the concentrations of water inside and outside the cell become equal
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outer surfaces of the cells of bacteria, plants, fungi, and some protists are covered with non living, typically stiff coatings called....
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cell walls
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cell walls are produced by....
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the cells they surround
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what do plant cells secrete though their plasma membrane, forming the primary cell wall?
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cellulose
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a layer made of primarily pectin, that joins the primary cell walls of adjacent cells
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middle lamella
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what does pectin solidify?
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jelly
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the structure that governs the interactions that occur between a cell and its external environment is the...
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plasma membrane
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acts as a gate keeper, allowing only specific substances in or out and passing chemical messages from the external environment to the cell's interior
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plasma membrane
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_____ form compartments in which specialized biochemical activities can occure
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internal membranes
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____ are responsible for the isolating function of membranes
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lipids
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____ regulate the exhange of substances and communication with the environment
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proteins
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the head of a phospholipid is?
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polar and hydrophilic
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a phospholipid is?
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non polar and hydrophobic
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consists of all a cell's internal contents (including all the organelles except the nucleus, in eukaryotes), mostly made of water
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cytoplasm
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most biological molecules, including salts, amino acids, and sugars, are polar and water soluble, and so are _____.
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hydrophilic
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in most animal cells, the phospholipid bilayer of membranes also contains ______.
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cholesterol
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what are some ways that cholesterol affects membrane structure and function?
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1. it makes the bilayer stronger
2. more flexible but less fluid 3. less permeable to water soluble substances such as ions and monosaccharides |
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glycoproteins
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proteins that are embedded within or attached to the surface of a membrane's phospholipid bilayer
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regulates the movement of hydrophilic molecules through the plasma membrane
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transport proteins
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form pores or channels that allow small water-soluble molecules to pass through the membrane. specific to potassium, sodium, and calcium
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channel proteins
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have binding sites that can temporarily attach to specific molecules on one side of the membrane
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carrier proteins
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