BioChem Test 3
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- Catabolism is an essentially __________ process.
- exothermic
- Direct phosphorylation of glucose by ATP leads to the formation of
- glucose-6-phosphate
- Glycolysis occurs within the
- cytoplasm
- What sugars can enter the glycolysis pathway?
-
glucose
fructose
galactose - What coenxyme is used in most oxidation-reduction reactions of carbohydrate catabolism?
- NAD/NADH
- What is the product of the first stage of glycolysis?
- glyceraldehyde-3-phosphate
- The net ATP output for glycolysis is ____ per glucose molecule.
- 2 ATP
- What is the final product of glycolysis?
- pyruvate
- What coenzyme must be reoxidized so that glycolysis can continue?
- NADH
- Under aerobic conditions in the body, pyruvate is converted to
- acetyl-CoA
- Under anaerobic conditions in muscle cells,pyruvate is converted to:
- lactate
- The production of triose phosphates in the first stage of glycolysis is an endothermic sequence of reactions.
- True
- The oxidative(aerobic) reactions of metabolism occure in the:
- mitochondria
- The direct precursor for the citric acid cycle is:
- acetyl-CoA
- One turn of the Kreb's cycle produces____ molecules of CO2.
- 2 CO2
- The products of the tricarboxylic acid cycle are carbon dioxide and:
-
3 NADH
1 FADH2
1 GTP - The electron transport system (ETS) or respiratory chain is found dispersed in the mitocondrial matrix.
- False
- What metal ions present in the cytochromes of the ETS aid in the passage of electrons down the chain?
- Fe++ and Fe+++
- The final acceptor of electrons (H atoms) during respirations is:
- O2
- The formation of ATP in the ETS is called:
- oxidative phosphorylation
- It is possible to oxidize the hydrogen atoms of acetyl-SCoA without having oxidative phosphorylation occur.
- True
- The majority of the ATP produced during the catabolism of glucose is formed during:
- oxidative phosphorylation
- Glycogenolysis directly leads to the formation of glucose-6-phosphate which undergoes glycolysis.
-
False
glycogenolysis--> gulcose-1-phosphate - An important product of the pentose phosphate pathway (shunt)is:
- NADPH
- Another important product of the pentose shunt besides NADPH is :
- ribose-5-phosphate
- NADH is the coenzyme used in anabolism(synthesis).
-
False
oxidation - The protein complex which is responsible for respiration is imbedded in the inner mitochondrial membrane.
- True
- Before fats and oils can be metablized, fatty acids must be released from triglycerides with the aid of a triglyceride lipase.
- True
- The catabolism of fatty acids is called beta-oxidation.
- True
- The activator/carrier molecule used in fatty acid catabolism is:
- coenzyme-A, CoASH
- Complete beta-oxidation of a 12 carbon fatty acid produces ____ molecules of acetyl-CoA.
- 6 acetyl-CoA
- Beta-oxidation occurs in the cytoplasm of a cell.
-
False
occurs in mitochondria - Fatty acid synthesis is the complete reverse of beta-oxidation.
- False
- The protein which is responsible for the transport of fatty acids through the inner mitochondirial membrane into the matrix is:
- carnitine
- The synthesis of a 12 carbon fatty acid is achieved by the sequential condensation of 6 acetyl-CoA molecules.
- False
- What coenzyme is the reducing agent used in fatty acid biosynthesis?
- NADPH
- The key intermediate in fatty acid synthesis is the free three carbon acid derivative, malonate.
- False
- Ketone bodies are formed when the concentration of aceytl-CoA in the mitochondria is very high.
- True
- In the cytoplasm, acetyl-CoA is used in the synthesis of non-saponifiable lipids.
- True
- The activator/carrier molecule used in fatty acid biosynthesis is:
- ACP
-
Which of the following is a ketone body:
acetyl-CoA
acetone
acetaldehye
malonyl-CoA - acetone
- The most important functions of aminoacids is for the synthesis of:
- Proteins
- Two key aminoacids in the catabolism of the amino group of amino acids are glutamate and ___________.
- aspartate
- Oxidative deamination of aminoacids directly produces:
- ammonium ion (NH4+)
- The direct "fuel" for the urea cycle is:
- carbamoyl phosphate
- The production of glutamate from alpha-ketoglutarate is called:
- transamination
- The molecule which reacts with carbamoyl phosphate at the start of the urea cycle is oxaloacetate.
- False
- The second amino group of urea is derived from aspartate.
- True
-
Which of the following can NOT enter the glycolysis pathway?
glucose
fructose
galactose
glycogen - glycogen
- What is the product of the endergonic stage of glycolysis?
- glyceraldehyde-3-phosphate
- Glyceraldehyde-3-phosphate and dihydroxyacetonephoshate are:
-
trioses
functional isomers
monosaccharides - Gluconeogenesis is the production of glucose from non-carbohydrate sources.
- True
- The synthesis of a 12-carbon fatty acid is achieved by the sequential condensation of 6 malonyl ACP
- True
- The key indermediate in fatty acid synthesis is the free three carbon diacid, malonate.
-
False
malonyl-SCoA - Ketone bodies are formed when the concentration of acetyl-CoA in the Cytoplasm is very high.
-
False
mitochondria - The molecule which reacts with carbonmoyl phosphate are the Start of the urea cylce is Aspartate.
- True