AP Biology Exam Review-Chapter 5: Cell Respiration by platarozaluna

AP Biology Exam review taken from Barron's Chapter 5: Cell Respiration
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what is cell respiration?
an oxidative process by which cells extract energy stored in food and transfer that energy to molecules of ATP
what happens to the energy stored in ATP?
it is instantly available for cellular work
what is the equation for aerobic respiration?
C₆H₁₂O₆ + 6O₂ --> 6H₂O + 6CO₂ + energy
what are the two types of cellular respiration?
aerobic (oxygen) and anerobic (no oxygen)
what are the steps of anaerobic respiration?
glycolysis, and then lactic acid or alcohol fermentation
what are the steps of aerobic respiration?
glycolysis, Krebs Cycle, ETC, oxidative phosphorylation
what does a molecule of ATP consist of?
adenosine, and three phosphates
why is ATP unstable?
the three phosphates are all negative and repel one another
why is ADP stable?
one phosphate is removed from ATP by hydrolysis
what is glycolysis?
a ten-step process that breaks down 1 molecule of glucose (a six-carbon molecule) into two three-carbon molecules of pyruvate and pyruvic acid and releases 4 ATP. It requires a 2 ATP activation, so the net gain is 2 ATP
what is the equation for glycolysis?
2 ATP+1 Glucose= 2 Pyruvate+4 ATP
where does glycolysis occur?
cytoplasm, and it does not require oxygen
what is pyruvate the raw material for?
Krebs Cycle
What is ATP produced by in glycolysys?
substrate-level phosphorylation
what is substrate-level phosphorylation?
direct enzymatic transfer of a phosphate to ADP by kinase
what enzyme catalyzes the third step of glycolysis?
PFK-phosphofructokinase. It inhibits glycolysis, stopping it when the cell ahs enough ATP (allosteric inhibitor)
what is fermentation?
anerobic, catabolic process that consists of glycolysis plus lactic acid or alcohol fermentation. It originated when there was no free oxygen in the atmosphere of earth.
what is a facultative anaerobe?
can tolerate the presence of oxygen, but simply do not use it
what is an obligate anaerobe?
cannot live in an environment containing oxygen
what is alcohol fermentation?
cells convert pyruvate to ethyl alcohol and carbon dioxide, which is released as a waste product. In the porcess, NADH is oxidized back to NAD

-used by bread and beer industries
what is lactic acid fermentation?
pyruvate from glycolysis is reduced to form lactate and NADH gets oxidized back to NAD

-used by human skeletal muscles when they get tired
-used to produce yogurt and cheese
-lactate can be converted back to pyruvate in the liver if oxygen is returned to the muscles
what is the Krebs cycle of aerobic respiration?
also called citric acid cycle
takes place in mitochondrial matrix and requires pyruvate
turns twice
pyruvate combines with coenzyme A to form acetyl CoA
each turn releases 3 NADH, 1 ATP, 1 FADH and the waste product, CO2
ATP is produced by substrate level phosphorylation
what is the structure of the mitochondrion?
enclosed by a double membrane, outer is smooth but the inner (cristae) is folded
the christae had two compartments, the outer and the matrix
Krebs occurs in the matrix
what are NAD and FAD?
coenzymes that carry electrons (H+) along the ETC

NAD and FAD are oxidized, NADH and FADH are reduced
what is the electron transport chain?
proton gradient/proton pump

think of traveling hydrogens
what is chemiosmosis?
Hydrogen atoms diffuse down their concentration gradient out of the thylakoid into the stroma through ion channels in the membrane.
how much ATP total is formed in glycolysis?
38 total, 36 net
where does 90% of ATP formation take place?
chemiosmosis
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