Exam 2 Review Part II

Question 1

What molecules are responsible for the formation of the spliceosome complex?

Answer 1

Small nuclear RNAs

Question 2

True or False

Chloroplasts and mitochondria use their own unique genetic code.

Answer 2

True

Question 3

Name the 3 tRNA binding sites formed by a ribosome for translation of a protein

Answer 3

P-peptidyl
A - aminoacyl
E - Exit

Question 4

How many possible stop codons are there in eukaryotic mRNA?

Answer 4

3:
UAG
UAA
UGA

Question 5

During translation, the role of enzyme peptidyl transferase is

A. Transfer of a phosphate group

B. Amino acid activation

C. Peptide bond formation between adjacent amino acids

D. Binding of ribosome subunits to mRNA

Answer 5

C. Peptide bond formation between adjacent amino acids

Question 6

As part of an early experiment on the secretory system, an in vitro translation system consisting only of mRNA and ribosomes resulted in proteins that were larger than the identical protein when translated in a cell. Why did this happen?

Answer 6

Signal sequence cleavage requires ER entry and the action of ER-resident proteins

Question 7

Mitochondrial proteins transcribed from the nuclear genome are:

Answer 7

Synthesized by free cytosolic ribosomes and brought to the mitochondrial membrane in an unfolded form by chaperone proteins such as Hsp70

Question 8

GLUT (glucose transporters) proteins transport glucose from the blood to cells. Which of the following statements about them are FALSE?

A. GLUT proteins are an example of active transport

B. GLUT proteins require ATP to transport glucose across the cell membrane

C. Binding of glucose to the transporter protein leads to a conformation change and the transport of glucose to the other side of the membrane.

D. GLUT proteins can only transport proteins from the outside of the cell to the cytoplasm

E. A, B and C

F. A, C and D

G. A, B and D

F. B, C and D

Answer 8

G. A, B and D

A. GLUT proteins are an example of active transport

B. GLUT proteins require ATP to transport glucose across the cell membrane

D. GLUT proteins can only transport proteins from the outside of the cell to the cytoplasm

Question 9

Nuclear export of proteins from the cytoplasm occurs through _______ using the nuclear cargo protein _______.

Answer 9

C. nuclear pore complexes; exportin

Question 10

What are the important ER-resident enzymes that modify proteins in the secretory pathway?

Answer 10

Oligosaccharyl transferase and Protein disulfide isomerase

Question 11

Briefly describe allosteric regulation of an enzyme

Answer 11

Allosteric regulation refers to the process for modulating the activity of a protein by the binding of a ligand to a site topographically distinct from the site of the protein

Question 12

List these molecules in order from most to least permeable through a lipid bilayer: peptide, carbon dioxide, calcium ion, glucose

Answer 12

Carbon dioxide, glucose, calcium ion, peptide

Question 13

Which of the following statements is true regarding regulation of glycolysis

A. Hexokinase regulates glycolysis by degrading glucose-6-phosphate

B. Low levels of ATP inhibit phosphofructokinase-1 because ATP preferentially binds to the allosteric inhibition site.

C. Inhibition of glucose-6-phosphate by hexokinase is an example of feedback inhibition

D. None of these statements are correct.

Answer 13

C. Inhibition of glucose-6-phosphate by hexokinase is an example of feedback inhibition

Question 14

What source of energy is needed for unidirectional translocation of a protein into the mitochondrial matrix?

Answer 14

ATP

Question 15

Which of the following statements regarding the electron transport chain is TRUE?

A. Cytochrome c transports electrons from complex I and complex II to ATP synthase

B. Cytochrome oxidase (complex IV) accepts electrons from cytochrome c

C. Only complex II (succinate-CoQ reductase) pumps protons directly across the inner mitochondrial membrane

D. Coenzyme Q resides in the mitochondrial matrix

Answer 15

B. Cytochrome oxidase (complex IV) accepts electrons from cytochrome c

Question 16

The citric acid cycle consists of the oxidation of ________ to produce _____,_____, and _____.

Answer 16

acetyl CoA; NADH, FADH2, and ATP

Question 17

The energy required to drive the transport of small molecules in and out of the mitochondrial matrix is provided by:

Answer 17

The electrochemical gradient

Question 18

What source of energy is needed for unidirectional translocation across the membrane during cotranslational translocation into the endoplasmic reticulum?

Answer 18

GTP hydrolysis

Question 19

In terms of its role in the generation of metabolic energy, the thylakoid membrane of chloroplasts is equivalent to the ___________ of mitochondria.

A. Outer membrane
B. Inner membrane space
C. Matrix
D. None of the above

Answer 19

D. None of the above

Question 20

True or False
GTP can easily be converted to ATP in the cell, meaning that GTP produced during the citric acid cycle can feed directly into powering ATP synthase

Answer 20

True

Question 21

Which statements are correct in regards to the formation of chloroplasts?

A. Chloroplasts contain special light-harvesting pigments in their thylakoid membranes that are responsible for the light reactions of photosynthesis

B. All plastids, including chloroplasts, develop from proplastids that are capable of converting from one plastid type to another

C. The thylakoid membrane is equivalent to the outer mitochondrial membrane in that it is the sight of ATP synthesis

D. Chromoplasts are specialized plastids that contain different pigment proteins than chlorophyll, but are also able to participate in photosynthesis

E. A and B

F. A and C

G. A and D

Answer 21

F. A and B

A. Chloroplasts contain special light-harvesting pigments in their thylakoid membranes that are responsible for the light reactions of photosynthesis

B. All plastids, including chloroplasts, develop from proplastids that are capable of converting from one plastid type to another

Question 22

The inner mitochondrial membrane contains proteins that

Answer 22

Synthesize ATP, pump protons, and transport pyruvate

Question 23

Chloroplasts are similar to mitochondria in that both

Answer 23

Have a porous outer membrane

Question 24

The inner compartment of mitochondria is called the

Answer 24

Matrix

Question 25

Where does the Calvin cycle occur in chloroplasts?

Answer 25

The Stroma