Chapter 7 Flashcards
Autotrophs
Heterotrophs
Cellular respiration
metabolic harvesting of energy by oxidation
Dehydrogenation
chemical reaction involving loss of a hydrogen atom
During __________, loss of electrons is accompanied by loss of protons.
Dehydrogenation
Cellular respiration is a series of _____ reactions
redox
NAD+ accepts ____ electron(s) and ______ proton(s)
2; 1
The reduced form of NAD+ is _________
NADH
In aerobic respiration, the final electron acceptor is ________
oxygen
In anaerobic respiration, the final electron acceptor is ________
an inorganic molecule
In fermentation, the final electron acceptor is ________
an organic molecule
Substrate-level phosphorylation
ATP is formed by transferring a phosphate group to ADP
Oxidative phosphorylation
synthesis of ATP by ATP synthase using energy from a proton (H+) gradient
Why have energy released in multiple small steps?
Larger release of energy in a single step = more energy lost as heat, less useable energy
Glycolysis
anaerobic breakdown of glucose
Where does glycolysis occur?
Cytoplasm
Glycolysis yields two _______ with a net of two _______
pyruvate; ATP
T or F: Glycolysis requires oxygen
F: Glycolysis does not require oxygen
In glycolysis, _______ is converted into two pyruvate
glucose
In glycolysis, glucose is converted into two _________
pyruvate
pyruvate is a ____ carbon molecule
3
What happens in the first 5 reactions of glycolysis?
glucose is converted into two G3P
What happens in the second 5 reactions of glycolysis?
G3P is converted into pyruvate
Glycolysis: priming reactions
Two high-energy phosphates from two ATP molecules are added to glucose, producing 6-carbon molecule with 2 phosphates
Glycolysis: cleavage
6-carbon diphosphate sugar is split into two 3-carbon monophosphate sugars
Hydrolysis of one ATP molecule yields a delta-G of ________ kcal/mol
-7.3
What three changes occur in glycolysis?
- Glucose is converted into two pyruvate molecules
- Two ATP molecules are converted into ATP via substrate-level phosphorylation
- Two NAD+ molecules are reduced to NADH
Inputs and outputs of glycolysis
glucose -> pyruvate
2 NAD+ -> 2 NADH
2 ADP -> 4 ATP (2 net ATP)
In the oxidation of pyruvate, the acetyl group is bound to coenzyme A to produce ________
acetly-CoA
What enzyme is involved in pyruvate oxidation?
Pyruvate dehydrogenase
Which part of acetly-CoA is fed into the CAC?
acetyl group
Which part of acetly-CoA is recycled?
coenzyme A
What are the other names for the citric acid cycle?
TCA cycle, Krebs cycle
Where does the citric acid cycle take place?
Matrix of mitochondria