Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
90 Cards in this Set
- Front
- Back
Disorder happens
|
spontaneously
|
|
Organization requires
|
Energy
|
|
entropy gain
|
All energy transformations result in an
increase of “disorder” |
|
free energy (G
|
Useful energy = Gibbs
|
|
Metabolism
|
the sum of all
biochemical reactions in a cell |
|
Two kind of
metabolism |
Anabolism
synthesis reactions (building something) Catabolism decomposition reactions (breaking something down) |
|
The capacity to do “work”
|
Energy
|
|
Different types of energy
|
potential energy
• kinetic energy • chemical energy (energy in bonds) • radiation energy (light) • nuclear energy • heat (kinetic energy of molecules) |
|
Heat energy is measured in
|
Kilocalories
|
|
One calorie = the amount of heat required to raise the
temp of 1 g water by 1C |
1 food Calorie = 1 kilocalorie (kcal) = 1000calories
|
|
First law of thermodynamics
|
Any form of energy can be transformed to other
forms of energy, but energy is never lost or created. The sum of all energy is always the same •energy cannot be lost-only converted |
|
Second Law of Thermodynamics:
|
disorder is more likely than order
•Entropy is always increasing Entropy = disorder in the universe |
|
Free energy change ^ (G)
|
The amount of energy needed for a reaction to proceed
|
|
exergonic reaction:
|
releases energy
|
|
endergonic reaction
|
Gains energy
|
|
Activation energy
|
energy needed to get a reaction started
|
|
Catalysts
|
substances that lower the activation energy of a reaction
|
|
ATP
adenosine tri-phosphate |
energy from exergonic reactions is used to fuel endergonic reactions
|
|
Enzymes
|
molecules that catalyze reactions in living cells
|
|
Enzymes are very
|
specific
|
|
substrate
|
The reactant(s) that are used to accelerate a reaction
|
|
Inhibitors
|
are molecules that bind to the enzymes and decrease activity
|
|
competitive inhibitors
|
compete with the substrate for binding to the same active site
|
|
Activators
|
molecules that bind to the enzymes and increase activity
|
|
Cofactors
|
non- protein molecule/atom required for enzyme activity
Metal or co-enzyme (like vitamins |
|
Feedback
inhibition |
when the initial enzyme is inhibited by the final product
|
|
All organisms use cellular respiration to
|
extract energy from organic molecules
• Glucose to ATP It occurs in all tissues at all times |
|
autotrophs
|
are able to produce their own organic
molecules through photosynthesis |
|
heterotrophs
|
live on organic compounds produced by other organisms
|
|
A redox reaction
|
where one reactant is
oxidized (loses e-) and the other reactant is reduced (gains e-) |
|
Nicotinamide adenine dinucleotide (NAD+,becomes NADH)
|
used to move electrons in cellular respiration
NAD+ is an electron carrier •NAD+ accepts 2 electrons and 1 proton to become NADH |
|
Aerobic respiration
|
In the presence of oxygen this large amount of energy must be released in small steps rather than all at once
|
|
C6H12O6+ 6O2>6CO2+ 6H2O + 36 ATP + heat
|
The equation for cellular respiration
|
|
Steps of Cellular Respiration are:
|
1 Glyucolysis
2 Pyruvate Oxidation (AcetylCoA) 3 The Krebs Cycle (Citric acid cycle) 4 Electron Transport Chain (ETC) 5 Chemiosmosis (Oxidativephosphorylation) |
|
Enzymatic reaction rate
is influenced by several factors: |
Enzyme concentration
• Substrate concentration *all enzymes are busy • Environment • Regulatory molecules |
|
e- and H+ are transferred from glucose to
oxygen through a series of oxidations • High energy e- in sugars to low energy e- in CO2 and H2O |
Cellular Respiration
|
|
Occurs outside the mitochondria
• Splits the C6 sugar glucose into 2 C3 sugars called pyruvate |
Glycolysis
|
|
converted into Acetyl CoA
• This gives off a CO2 and gives a NADH |
Pryruvate Oxidation
|
|
The acetyl CoA enters the cycle and results in:
2 CO2 given off 3 NADH produced 1 ATP produced 1 FADH produced • *multiply times 2 to figure out “per glucose” |
The Krebs Cycle
|
|
The NADH and FADH give their electrons
electrons “tumble” down it losing energy as they go • This results in protons being pumped out of the inner mitochondrial membrane and creates a proton gradient • The electron is given to O2 at the end thus“aerobic respiration” |
Electron Transport Chain
|
|
The protons accumulate and are passed back over
the membrane through the ATP synthase protein • For each proton that comes through, ADP + P is changed into ATP |
Chemiosmosis
(Oxidative phosphorylation) |
|
Theoretical energy yields
|
38 ATP per glucose for bacteria
• 36 ATP per glucose for eukaryotes |
|
Actual energy yield
|
30 ATP per glucose for eukaryotes
• reduced yield is due to “leaky” inner membrane and use of the proton gradient for purposes other than ATP synthesis |
|
use of inorganic molecules (other than O2) as final
electron acceptor |
anaerobic respiration
|
|
use of organic molecules as final electron acceptor
Ethanol, lactic acid |
fermentation
|
|
“switching over” to fermentation when O2 is not available
|
facultative anaerobic
|
|
the lack of O2 eliminates all steps but
|
glycolysis
|
|
important because many of the intermediates are starting molecules for other cell parts and functions
|
Respiration
|
|
Protons accumulate and are passed back to the other side ADP + P is turned back into ATP
|
ATP synthase
|
|
A polar molecule due to its oxygen that has a slight negative charge while its hydrogens have slight positive charge is a universal solvent and essential to all life
|
water
|
|
Power House of the cell, where ATP is made
|
mitochondria
|
|
Changed into ATP
|
ADP + P
|
|
Net total of energy made through cellular respiration
|
36 ATP
|
|
Eases the fall of electrons negative charge helps drive protons across membranes
|
Proton Gradient
|
|
Products of Glycolysis step #1
|
2 ATP and 2 NADH+
pryruvic acid |
|
Products of Pryruvate Oxidation Step #2
|
Acetyl CoA
|
|
Products of the Krebs Cycle
|
CO2
3 NADH 1 ATP and 1 FADH ( total is x 2) and citric acid |
|
Has no products excpet it makes the proton gradient: oxygen is final electron acceptor
For each NADH 3 protons are pumped out For each FADH 2 protons are pumped out |
Electron Transport Chain
|
|
What organisms do both cellular respiration and photosynthesis
|
Plants
|
|
captures light energy from the sun and convert it to chemical energy stored in sugars and other organic molecules countered by cellular respiration
|
photosynthesis
|
|
Photosynthesis is carried out by:
|
Cyanobacteria
• 7 groups of algae • all land plants |
|
The equation for cellular respiration
|
6CO2 + 6H2O -> C6H12O6 + 6O2
|
|
Photosynthesis takes place in
|
chloroplasts
|
|
internal membrane arranged in flattened sacs
contain chlorophyll and other pigments |
Thylakoid membrane
|
|
Semi -liquid substance surrounding thylakoid membranes
|
Stroma
|
|
Capture energy from sunlight
Make ATP and reduce NADP+ to NADPH In thylakoid |
Light dependent reactions
|
|
Use ATP and NADPH (from light reactions) to synthesize organic molecules from CO2 In stroma
|
Carbon fixation reactions
|
|
Photosynthesis is divided into:
|
Light dependent reactions
and Carbon fixation reactions |
|
the main pigment in photosynthesis
|
Chlorophyl
|
|
Chlorophyll mainly absorbs light in the
|
blue and red parts of the spectrum
No absorption in green and yellow |
|
increase the range of light wavelengths that
can be used in photosynthesis can protect the plant from excess light known as carotenoids |
accessory pigments
|
|
a team of light-gathering molecules
|
photosystem
|
|
absorbs photons and excites
electrons that are passed on to a protein carrier |
Photosystem II- happens first
|
|
absorbs photons and re-excites
electrons that are passed through carriers and ultimately reduce NADP+ to NADPH |
Photosystem 1
|
|
To build carbohydrates, cells need:
|
Energy, reduction potential, a source of Carbon
This all happens in the Calvin Cycle |
|
Calvin cycle has 3 phases:
|
1 carbon fixation
2 Reduction 3 regeneration of Rubisco (RuBp) |
|
This is the most abundant enzyme in the world
|
ribulose bisphosphate carboxylase oxygenase
(rubisco) |
|
In most plants the enzyme that “fixes” CO2 from the air
|
rubisco
|
|
2 G3P are used to produce 1 glucose in reactions
in the cytoplasm o each G3P contains 3 carbons • 18 ATP molecules • 12 NADPH molecules |
Make one molecule of glucose
|
|
There are two alternative methods of
photosynthesis that have evolved in high temperatures and arid climates |
C4 metabolism
• Crassulacean acid metabolism (CAM) |
|
a loss of energy
• inefficient photosynthesis It is a problem when: • the temp is high • it is too dry |
Photorespiration
|
|
Plants that only have rubisco have this
can combine with either O2 or CO2 occurs when rubisco binds with oxygen, instead of CO2 |
Photorespiration
|
|
Alternative methods use a different enzyme to
initially fix the CO2 from the air |
PEP carboxylase (PEPC)
|
|
separate the process in space with the CO2 being fixed in the mesophyll cells, and the Calvin cycle in the bundle sheath cells
|
C4 plants
|
|
separate the process between
night and day by using malic acid to store the CO2 |
CAM plants
|
|
Are carried out in the thylakoid • Convert light energy into ATP and NADPH • Split water and release O2 into the air
|
Light Reactions
|
|
Is carried out in the stroma • Uses ATP and NADPH to convert CO2 into a C3 sugar (G3P) •CO2 is fixed from the air by rubisco or pepc
|
Calvin Cycle
|
|
chloorphyll b, xanthophylls, and carotenes
|
accessory pigments
|
|
Carbon dioxide reacting with water forms this and Dissociates in to bicarbonate ions and hydrogen ions
|
carbonic acid
|
|
Color least effective in plant growth
|
Red because it absorbs the least amount of light
|