Citric Acid Cycle Flashcards
In a eukaryotic cell, most of the enzymes of the citric acid cycle are located in the
- Inner mitochondrial membrane
- Outer mitochondrial membrane
- Inter membrane space
- Mitochondrial matrix
Mitochondrial matrix
Pyruvate, the end product of glycolysis, enters the citric acid cycle after it has been converted to
- Acetyl CoA
- Lactic Acid
- Acetaldehyde
- Acetic acid
Acetyl-CoA
Most of the ATP made during cellular respiration is generated by:
- Photophosphorylation
- Oxidative Phosphorylation
- Glycolysis
- Substrate-level phosphorylation
Oxidative Phosphorylation
Energy that is released from glucose during respiration but not transferred to ATP bonds can be detected as
- heat
- CO2
- ADP
- H2O
Heat
Which metabolic pathway or process is common to both aerobic and anaerobic oxidation of sugar?
- Oxidation of pyruvic acid to CO2
- Kreb’s Cycle
- Glycolysis
- Chemiosmosis in mitochondrion
Oxidation of pyruvic acid to CO2
Which of the following statements about oxidative decarboxylation is true?
- does not occur in the TCA cycle
- involves loss of CO2 and the production of NAD
- involves loss of CO2 and the production of FADH2
- involves loss of CO2 and the production of NADH
involves loss of CO2 and the production of NADH
The citric acid cycle is involved in
- all of the choices
- generation of energy from pyruvate
- synthesis of fatty acids
- synthesis of amino acids
all of the choices
You may have learned the term “amphoteric” used in general chemistry to describe a substance that could function as either acid or base. When we describe the citric acid cycle as amphibolic, we mean that it:
- amplifies substrates so that large, rolling molecules are produced
- is capable of both synthetic and degenerative reactions
- is capable of every kind of reaction imaginable
- can carry out anabolic reactions
is capable of both synthetic and degradative reactions
Early life forms lived in an atmosphere largely devoid of free oxygen molecules. Most present-day life forms use molecular oxygen as:
- the final acceptor for electrons removed from carbons during oxidation
- starting materials for synthesis of lipids
- the final acceptor for electrons removed from hydrogen during digestion
- raw material for synthesis of DNA
the final acceptor for electrons removed from carbons during oxidation
The citric acid cycle is occasionally called the Krebs Cycle in honor of its discoverer, Hans Krebs. It is also occasionally called the tricarboxylic acid cycle. Why?
- The citric acid cycle is amphibolic
- The first several reactions of the citric acid cycle produces tricarboxylic acids
- The final product of the citric acid cycle is a ticarboxylic acid
The first several reactions of the citric acid cycle produces tricarboylic acids
Ordinarily, entrance of the carbons of pyruvic acid into the TCA cycle requires loss of one of the carbons. There is, however, an enzyme that can insert all three of the carbons of pyruvate into the TCA cycle. This enzyme is known as
- a-ketoglutarate dehydrogenase
- Citrate synthase
- Pyruvate carboxylase
- Pyruvate dehydrogenase
Pyruvate carboxylase
This is one of the by products of the citric acid cycle
- methane
- water
- carbon dioxide
- ethanol
carbon dioxide
How many energy-rich molecules (excluding NADH and FADH2) are produced when one molecule of acetyle-CoA enters the citric acid cycle?
- 2
- 4
- 3
- 1
1
How many FADH2 are produced in the citric acid cycle when two acetyl-Coa molecules enter>
- 4
- 2
- 1
- 3
2
What is the approximate total yield of ATP that is produced via the Krebs cycle and subsequent oxidative phosphorylation of a single molecule of acetyl-CoA?
- 32
- 20
- 10
- 16
10
