PCB 3134 UF EXAM 3

According to the DNA double helix model, the distance from the phosphorus atom of the backbone to the center of the axis is...

1 nm

Plasmodesmata are cell-cell interaction structures found in plants. Plasmodesmata contain a dense central structure called desmotubule, which is derives from...

the smooth endoplasmic reticulum

The structure of a DNA molecule can be changed by different enzymes. An enzyme that creates a transient break in both strands of a DNA duplex and then allows another DNA fragment to pass through to form or relax supercoil is called a...

type II topoisomerase

DNA renaturation is the basis of many DNA analysis methods. Which of the follow techniques is NOT based DNA renaturation...

DNA gel electrophoresis

During muscle contraction, the length of which region of the sarcomere stays unchanged...

A bands

When an action potential arrives, it is transduced to the sarcoplasmic reticulum (SR) by a special structure called...

transverse tubule

In the ER, during the modification of the core oligosaccharide on glycoproteins, two of the three terminal glucose residues are removed. The remaining glucose bonds to an ER chaperone protein called calnexin to help the glycoprotein to fold properly. The remaining glucose is then removed by ... to release the glycoprotein from the chaperone.

glucosidase II

In response to the accumulation of misfolded proteins, genes encoding what kinds of proteins are not induced during the unfolded protein response (UPR)...

ER-based secretory proteins

A complex eukaryotic genome generally has three broad classes of DNA sequences. Which class of DNA sequences contains the greatest amount of genetic information...

nonrepeated DNA sequences

How are membranes thought to be made?

a. Membranes are made de novo.

b. Membranes are made as new entities from pools of proteins and lipids.

c. Membranes arise from pre-existing membranes.

d. Membranes arise as newly made proteins and lipids are inserted into the ER membranes.

c and d

In muscle cells, how is the arrangement relative to one another of thin and thick filaments as seen in a cross-sectional electron micrograph described...

thin filaments in a hexagonal array around each thick filament.

In the endocytic pathway, endocytotic vesicles fuse with each other to form..., in which the pH is lowered to about 6.0 by...

early endosomes, H+-ATPases in the membrane

Plasmodesmata are plant cytoplasmic channels that pass through the cell wall of adjacent cells. The plasmodesmatal pore is capable of dilation, allowing molecules up to... kDa to pass between cells.

50

Proteins destined for peroxisomes possess a peroxisomal targeting signal (PTS). The PTS will be recognized by the PTS receptor in...

cytosol

Proteins maintained in the membrane of the endoplasmic reticulum contains a short amino acid sequence at the C-terminus as a retrieval signal, which is...

KKxx

Lysosomes are found in animals but not in plants. Which of the following descriptions is NOT correct for lysosomes...

Lysosomes have double membranes.

Proteasomes are hollow, cylindrical, protein degrading machines found in both the cytosol and the nucleus of cells. A protein that is to be degraded by a proteasome is labeled by...

a polyubiquitin chain

At the trans-Golgi network, the formation of clathrin-coated vesicles is initiated by a small GTP-binding protein named...

ARF1

The eukaryotic cilia and flagella have a complex structure. The core of a cilium/flagellum is called the..., which contains ... and ...

axoneme, 9 peripheral doublet microtubules, 2 single central microtubules.

The endomembrane system functions as a coordinated unit, which includes which of the following organelles?

a. lysosomes

b. vacuoles

c. endosomes

d. Golgi complex

e. endoplasmic reticulum

a,b,c,d, and e

The enzyme that catalyzes the excision of a transposon from a donor DNA site and subsequent insertion a a target DNA site is called... This enzyme is encoded by...

transposase, transposon DNA

The pectins and hemicellulose found in plant cell walls are synthesized in...

the Golgi complex

There are a large number of integral proteins that are involved in cell-cell adhesion. Which of the following integral proteins do not require Ca2+ when they mediate cell-cell interactions...

immunoglobulin superfamily proteins

There are some "footprints" that can be used to identify site in the genome, which used to be occupied by transposable elements. These "footprints" are...

direct repeats of recipient DNA

The wall of a microtubule is composed of globular proteins arranged in longitudinal rows, termed protofilaments. Microtubules consist of ... protofilaments aligned side by side in a circular pattern within the wall.

13

Golgi complexes contain flattened disklike membranous cisternae, with dilated rums and associated vesicles and tubules. Typically, in each Golgi complex, fewer than ... cisternae are arranged in an orderly stack

eight

Muscle contraction uses energy from hydrolysis of ATP. After ATP binds to a myosin head, it is hydrolyzed to ADP and Pi. What happens after the bound Pi is released...

Release of the bound Pi induces a large conformational change in the myosin head.

What parts of the molecular motor dynein is responsible for traveling along microfilaments...

none of the others

Gene duplication often occurs during meiosis. What process is generally thought to produce gene duplication...

unequal crossing over

When a cilium or a flagellum emerges from a basal body, ... moves building materials to the assembly site at the tip of the growing axoneme.

kinesin

When proteins are synthesized on ER membrane-bound ribosomes, the signal peptide emerging from the ribosome binds to the signal recognition particle (SRP) complex. The SRP complex contains...

proteins and small RNAs

Which of the following molecular motors is known to mostly travel along microtubules to the plus end of the microtubules?

kinesins

Which of the following is a general description of a type II myosin motor?

a pair of globular heads each with a catalytic site, a pair of necks and a single, long, alpha-helical coiled-coil tail

Which of the following proteins are NOT made on ribosomes attached to the cytosolic surface of the ER?

proteins to be incorporated into peroxisomes

Which of the following is a correct description of the transmembrane sequence which blocks further translocation of the peptide through the channel in the ER membrane during synthesis?

at least 15 continuous hydrophobic or uncharged amino acids