Bio Chem 265 Final Exam Practice Test and Homework 45 Questions with Verified Answers
In class, we discussed the fact that glycolysis, the citric acid
... [Show More] cycle, and the electron transport chain, are intimately connected. Which description below is a description of glycolysis?
a)Cyclic pathway which produces NADH, GTP, and reduced coenzyme Q.
b) Cyclic pathway which converts ammonia into urea using 3 ATP molecules.
c) Linear pathway that converts pyruvate into glucose while oxidizing NADH.
d) Linear pathway which produces NADH and ATP as well as pyruvate. - CORRECT ANSWER d
Pick the statement that best describes the structure and characteristics of RNA.
a) Major form is double stranded helix with base pair stacking
b) Major form is constrained in the nucleus associated with histone proteins
c) Occurs in a variety of forms with the Ribose sugar Carbon #2 always chiral
d) Occurs in a variety of forms with the Deoxyribose sugar Carbon #2 always achiral - CORRECT ANSWER c
The name of the complicated enzyme complex which must convert pyruvate into acetyl-CoA, is:
a) Carbonic Anhydrase
b) Phosphofructokinase 1
c) Glyceraldehyde Dehyrdogenase
d) Pyruvate Dehydrogenase - CORRECT ANSWER d
The brain and muscles may convert which compound below into pyruvate using Lactate Dehydrogenase? (Rxn: Lactic acid <---> Pyruvate) - CORRECT ANSWER a
When Lactate Dhydrogenase converts Lactic acid into Pyruvate, this is a(n):
a) Oxidation
b)Reduction
c) Combustion
d) Isomerization - CORRECT ANSWER a
What compound is reduced by Lactate Dehydrogenase?
a) FADH
b) NAD+
c) NADH
d) Lactic Acid - CORRECT ANSWER b
Coenzyme A is a cofactor for approximately what percentage of enzymes in mammals?
a) 1%
b) 4%
c) 12%
d) 40% - CORRECT ANSWER b
Fatty acids are broken down two carbons at a time. In the first reaction, two hydrogens are removed in the reaction and a double bond is formed. What type of reaction is this? (This process reduces FAD)
a) Oxidation
b) Reduction
c) Combustion
d) Dehydration - CORRECT ANSWER B
Free Energy is a concept that can be used to predict magnitude and direction of a process or reaction. What does the free energy function not tell us about the process?
a) Entropy magnitude and sign
b)Enthalpy magnitude and sign
c) Temperature
d) Rate - CORRECT ANSWER d
DNA forms a double helix under physiological conditions. Under what conditions will the strands dissociate into monomers?
a) Low Temperature
b) High Temperature
c) In aqueous environments
d) None of the above - CORRECT ANSWER b
What is missing in muscles, heart, and brain, when the Cori cycle is fully activated?
a) Nitrogen
b) Carnitine
c) Glyceraldehyde - 3 - Phosphate
d) Oxygen - CORRECT ANSWER d
During Fasting, which statement would be the most correct?
a) Insulin High, Glucagon High, Glucose High,
Epinephrine High
b) Insulin Low, Glucagon High, Glucose High, Epinephrine High
c) Insulin Low, Glucagon High, Glucose Low, Epinephrine High
d) Insulin High, Glucagon High, Glucose Low, Epinephrine Low - CORRECT ANSWER c
Which two gluconeogenic enzymes replace the glycolytic enzyme Pyruvate Kinase?
a) PEP Carboxykinase and Enolase
b) PEP Carboxykinase and Pyruvate Carboxylase
c) Pyruvate Carboxylase and Enolase
d) none of the above - CORRECT ANSWER b
In type two diabetes, insulin levels may be normal or elevated, but blood sugar may be uncontrolled. How do we explain this?
a) Increase Thyroid horomones
b) Insulin Resistance
c) Increase Cortisol
d) Increase Adrenalin - CORRECT ANSWER b
Error rates by polymerases partly determine the presence or absence of genetic abnormalities. Which polymerase below is the HIGHEST FIDELITY?
a) DNA polymerase
b) RNA polymerase
c) Same error rate
d) none of the above - CORRECT ANSWER a
Bilirubin is a degradation product of:
a) Heme (porphorins coordinated with Fe)
b) Thyroid Horomone
c) Glycogen
d) Excess dietary fiber - CORRECT ANSWER a
Which statement below describes vitamin D the best:
a) Helps retain Vitamin E in the reduced form
b) Fat soluble and utilized in teeth and bone deposition
c) Ascorbic acid
d) Contains Riboflavin used for Rib growth - CORRECT ANSWER B
In the electron transport chain, Oxygen acts as a final electron acceptor to form what compounds:
a) NaOH
b) Coenzyme Q
c) Water
d) Flavin adenine Dinucleotide - CORRECT ANSWER c
What is the force that actually produces ATP through ATP synthase in the ETC?
a) proton gradient
b) Cl-gradient
c) Phosphate gradient
d) Fatty acid oxidation - CORRECT ANSWER a
Lactic Acid has a pKa that is a full unit LOWER than acetic acid. What consequences arise from this fact? pKa lactic acid = 3.7 pKa acetic acid = 4.7
a) At pH 4, lactic and acetic acids will be the dominant forms
b) At pH 4, lactate and acetic acid will be the dominant forms
c) At pH 8, both will be in the acidic form
d) At pH 2, both will be in the basic form - CORRECT ANSWER b
DNA is composed of nucleic acids in a double strand such that the coding strand is arranged from the:
a) 5' - 3' carbons of deoxyribose
b) 5'- 3' of ribose
c) 3' - 5' carbons of deoxyribose
d) 5' - 3' carbons of ribose - CORRECT ANSWER a
The formation of a DNA double helix is favored at ambient temperatures due to which intermolecular forces?
a) H bonding
b) Hydrophobic
c) Dipole Dipole
d) all of the above - CORRECT ANSWER d
Phosphate and sugars link covalently to form what type of bonds in DNA and RNA structures?
a) ethers
b) diesters
c) thiols
d) disulfides - CORRECT ANSWER b
The genetic sequence is considered which level of structure in the DNA hierarchy?
a) primary
b) secondary
c) tertiary
d) quarternary - CORRECT ANSWER a
The DNA sugar phosphate structure carries an overall negative charge due to the pKa of one of the phosphate groups being much less that physiological pH, and another very close to physiological pH. What overall charge do histones carry on their surface?
a) negative
b) positive - CORRECT ANSWER b
Which pairing will probably be the most stable over time between the following?
a) A-U
b) A-T
c) C-G
d) none of the above - CORRECT ANSWER c
DNAs are generally longer, more stable, double stranded and less flexible than typical single stranded RNA molecules. T/F
a) T
b) F - CORRECT ANSWER T
When comparing the chemical composition of DNA and RNA, what are the two most outstanding differences?
a) methyl on thymine (carbon atom 5) in contrast to no methyl on uracil
b) difference in Carbon 2 oxidation state
c) RNA has a single stranded major form
d) all of the above - CORRECT ANSWER d
Which carbon of ribose is the base attached to in RNA?
a) 0
b) 1
c) 2
d) 3 - CORRECT ANSWER b
Carbon 1 of deoxyribose is an sp2 carbon. T/F
a) T
b) F - CORRECT ANSWER b
Carbon #2 is chiral in ribose of RNA. T/F
a) T
b) F - CORRECT ANSWER a
Linear Ribose contains an anomeric carbon at which position?
a) 4'
b) 3'
c) 2'
d) 1' - CORRECT ANSWER d
All sugars including ribose and deoxyribose have overall planar, sp2 structures. T/F
a) T
b) F - CORRECT ANSWER b
Mitochondrial DNA consists of a definitive number of genes. How many genes appear to be expressed in mitochondria?
a) 5
b) 25
c) 37
d) 52 - CORRECT ANSWER c
What very important process(es) is/are associated with mitochondria?
a) oxidative phosphorylation
b) energy production
c) induction of apoptosis
d) all of the above - CORRECT ANSWER d
DNA polymerases appear to be about 100 fold more reliable than RNA polymerases in terms of error rate. T/F
a) T
b) F - CORRECT ANSWER a
Glycolysis is considered a linear pathway which starts with glucose and ends with pyruvate. How many enzymes are present which cannot carry out the reaction in reverse?
a) 0
b) 1
c) 2
d) 3 - CORRECT ANSWER d
There are 10 reactions in glycolysis. How many reactions does it take to make glucose in gluconeogenesis?
a) 9
b) 10
c) 11
d) 12 - CORRECT ANSWER c
Pyruvate is a?
a) phosphodiester
b) ketone and carboxylic acid (alpha keto acid)
c)alcohol and phenyl
d) ketone and ether - CORRECT ANSWER b
What important molecule is pyruvate converted into in order to be used for the citric acid cycle?
a) Coenzyme A
b) acetyl CoA
c) glucagon
d) epinephrine - CORRECT ANSWER b
CoA is a cofactor for 4% of the enzymes in the body. What important process does Co-enzyme A help enzymes accomplish?
a) Acetylation and de-acetylation of substrates
b) Transfer 2 carbons from pyruvate to the Citric acid cycle
c) Donate two carbons to carnitine to move 2 carbon units to mitochondrial matrix
d) all of the above - CORRECT ANSWER d
Importantly, the endoplasmic reticulum is known for production of proteins. What other major class of biomolecules is a critical function of the E. R.?
a) lipids
b) Amylose
c) Amylopectin
d) Glycogen - CORRECT ANSWER a
If the overall value of the couple reaction of ATP hydrolysis and phosphorylation of glucose is -10kJ/mol, but the value for the phosphorylation reaction is +20kJ/mol, what must the min/max value be at for the hydrolysis of ATP and ADP to make the reaction go forward?
a) -10 kJ/mol
b) -20 kJ/mol
c) -30kJ/mol
d) -40kJ/mol - CORRECT ANSWER c
In a coupled reaction that requires electrons, NADH may be oxidized to what?
a) NADH2
b) NAD+
c) NADPH
d) NADP - CORRECT ANSWER b
The high energy bond formed from the reaction between CoA and two carbon donor is called
a) sulfhydrl
b) phosphodiester
c) thioester
d) secondary amide - CORRECT ANSWER c [Show Less]