exam 4 quiz Flashcards by Aubri Unknown

Which of the following statements about proteoglycans is true?

Question 1 options:

a) They consist of chains of repeating disaccharide units connected to a protein core.

b) They are found in very low amounts in the basement membranes.

c) They are extremely fragile and are restricted to selected tissues.

d) Both (b) and (c) are correct.

a. They consist of chains of repeating disaccharide units connected to a protein core.

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Which one of the following is not found in the extracellular matrix?

Question 2 options:

Collagen

Laminin

Fibronectin

Actin

actin

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Desmosomes are ________.

Question 3 options:

disk-shaped adhesive junctions

restricted to cardiac muscle tissue

devoid of cadherins, but rich in intermediate filaments.

All of these are correct answers

disk-shaped adhesive junctions

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In the early embryo, cells detach from an epithelium and transform into individual, migrating cells. This is thought to be due to _________________.

Question 4 options:

the cytoplasm taking on an anti-adhesive character

a loss of expression of E-cadherin genes

autophagy of the nucleus

an increase in the expression of E-cadherin genes

a loss of expression of E-cadherin genes

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Gap junctions are composed entirely of membrane protein subunits called __________.

Question 5 options:

Occludins

Claudins

Connexins

Connexons

Connexins

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Which of the following would cells interact with for the proper formation of a branching organ such as the salivary gland?

Question 6 options:

Collagen

Proteoglycans

Actin

Fibronectin

Laminin

Fibronectin

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What is the most plentiful protein in the human body?

Question 7 options:

ATP synthase

actin

myosin

collagen

collargen

collagen

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Which cell adhesion molecule below binds to a short sequence of carbohydrates on the cell surface?

Question 8 options:

adherins

cadherins

selectins

calmodulins

calpains

selectins

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Adherens junctions hold cells together using ____________ attached to ______________.

Question 9 options:

integrins; microfilaments

cadherins; microfilaments

cadherins; intermediate filaments

integrins; intermediate filaments

adherins; microfilaments

cadherins; microfilaments

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You inject a fluorescent dye into a single cell on the surface epithelium of a microscopic animal. After a brief period of time, the dye spreads to cells neighboring the injected cell. What does this suggest?

Question 10 options:

The cells are connected by gap junctions

The cells are connected by tight junctions

The cells are connected by plasmodesmata

The cells are connected by adherens junctions

The cells are connected by gap junctions

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Epithelial tissues _________.

Question 11 options:

consist of extracellular materials, including a variety of distinct fibers.

often contain cells scattered throughout the tissue

contain tightly packed cells and line spaces within the body.

All of these are correct

contain tightly packed cells and line spaces within the body.

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The degradation of extracellular materials is accomplished largely by_____________.

Question 12 options:

matrix metalloproteinases

ubiquitins

protein kinases

fibronectin

matrix metalloproteinases

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Which of the following statements about integrins is true?

Question 13 options:

They anchor cells to the substrate

All of these statements are true.

Different cell types are restricted to just one type of integrin

They are found in both animal and plant cells

They anchor cells to the substrate

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Why do cells flatten out as they make contact with a surface?

Question 14 options:

They lose water

They send out projections that make increasingly stable attachments.

They extrude cytoplasm

Their membranes stiffen

They send out projections that make increasingly stable attachments.

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Which of these cells would you expect to have very little or no integrin protein on the surface?

Question 15 options:

Red blood cells

Epidermal cells

Intestinal epithelial cells

Fibroblasts

Red blood cells

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A mutation in an integrin protein results in the deletion of the cytoplasmic domain. How will this affect the ability of a fibroblast to crawl?

Question 16 options:

There will be no effect

Its ability to attach and crawl will be greatly reduced because it will not be able to form focal adhesions

It will crawl faster because the integrins will be free to float in the membrane

Its ability to attach and crawl will be greatly reduced because it will not be able to form focal adhesions

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A mutation in the cytoplasmic domain of an integrin protein prevents it from binding to intermediate filaments. Which of these is a likely symptom?

Question 17 options:

a) There will be no effect

b) The epithelial layers of the skin will peel away and blister

c) The ability of neural crest cells to crawl will be reduced

Both b) and c)

b) The epithelial layers of the skin will peel away and blister

The tightest attachment between a cell and its extracellular matrix is seen at the site where an epithelial cell is attached to the underlying basement membrane. The specialized adhesive structure found at such a site is called a(n) ________.

Question 18 options:

hemidesmosome

tight junction

plasmodesma

spot desmosome

hemidesmosome

What kind of cell adhesion molecule on vessel walls mediates transient interactions to trap circulating white blood cells at sites of inflammation?

Question 19 options:

cadherins

selectins

IgSFs

integrins

selectins

Metastatic cells are distinguished by the fact that they ______.

Question 20 options:

are unable to invade other tissues, while normal cells can

are less adhesive than other cells.

are less adhesive than other cells and they are able to penetrate the basement membranes lining blood vessels.

are able to penetrate the basement membranes lining blood vessels

are less adhesive than other cells and they are able to penetrate the basement membranes lining blood vessels.

An enzyme that removes hydrogen ions from its substrate is a ________.

Question 1 options:

dehydrogenase

kinase

transferase

hydrolase

isomerase

dehydrogenase

H+ ions are able to enter the a subunit and bind to _____________, which then forms _____________ and causes the c subunit to rotate.

Question 2 options:

aspartate; aspartic acid

aspartame; aspartic acid

aspartic acid; aspartate

aspartame; aspartate

aspartate; aspartic acid

Which components of ATP synthase move/rotate?

Question 3 options:

c ring and alpha/beta hexamer ring

c ring, central stalk, alpha/beta hexamer ring

c ring, a subunit, and central stalk

c ring and central stalk

As the electrons are transferred from Cytochrome Oxidase (ETC complex IV) to an acceptor, the energy released is used to _____________.

Question 4 options:

transport protons against their concentration gradient to the intermembrane space

transport protons down their concentration gradient to the intermembrane space

synthesize ATP

recycle Cytochrome C

form the bonds in H2O

transport protons against their concentration gradient to the intermembrane space

An uncoupling protein often works by __________ the permeability of the ______________ membrane. Question 5 options: decreasing; inner mitochondrial decreasing; outer mitochondrial increasing; inner mitochondrial increasing; inner mitochondrial

increasing; inner mitochondrial

What is the purpose of uncoupling proteins in mammalian brown adipose tissue? Question 6 options: They help the tissue expand and contract when needed They allow muscles to contract more efficiently They function as a source of heat production during exposure to cold temperatures They give the tissue its color They allow the production of a larger number of ATPs per glucose

They function as a source of heat production during exposure to cold temperatures

What advantage do you think the cristae confer on the mitochondria? Question 7 options: They greatly increase the surface area for aerobic respiration machinery They allow swelling of mitochondria They activate the matrix They allow the mitochondria to shrink.

They greatly increase the surface area for aerobic respiration machinery

The inner mitochondrial membrane has characteristics in common with _________ Question 8 options: Bacterial cell membrane Cardiac muscle cell membrane

Bacterial cell membrane

What is the role of O2 in the electron transport chain? Question 9 options: Electron acceptor Binds to proteins Electron donor Fuel for heat

Electron acceptor

This graph illustrates the free energy relative to oxygen of the electron transport chain. The solid blue circles are electron carrier molecules, and the light blue ovals represent protein complexes. graph line goes down and it is talking about free energy vs direction of electron flow From an energy standpoint, are these reactions endergonic or exergonic? Endergonic Some are exergonic and others are endergonic There is not enough information Exergonic

exergonic

Where is ATP synthase located in eukaryotic cells? Question 11 options: Cytoplasm Inner mitochondrial membrane Outer mitochondrial membrane Matrix of mitochondria

Inner mitochondrial membrane

Where do the H+ ions accumulate as a result of the ETC? Question 12 options: Matrix Extracellular matrix Cytosol Intermembrane space

Intermembrane space

Which direction is the ATP synthase pointing? ***pic of atp synthase mushroom thing** Question 13 options: F0 base opens to Intermembrane space F0 base opens to Matrix

F0 base opens to Intermembrane space

Where does the ATP end up? ***pic of atp synthase mushroom thing** Question 14 options: Intermembrane space Extracellular space Matrix

Matrix

Which of the following describes what is happening when the beta subunit of the F1 region is in the loose conformation? Question 15 options: ADP and Pi are able to enter ADP and Pi are trapped ADP and Pi are released ADP and Pi combine to form ATP

ADP and Pi are trapped

What molecule accepts the electrons that drop off of the end of the mitochondrial electron transport chain? Question 16 options: NADPre H2O O2 NADre CO2

Which of the following complexes in the ETC pump H+ ions into the intermembrane space? Question 17 options: I, III, IV I, II, IV I, II, III, IV I and III

I, III, IV

What molecule is produced when electrons drop off of the end of the mitochondrial electron transport chain and attach to another molecule? Question 18 options: H2O CO2 NADre O2 NADPre

H2O

The TCA (Krebs) Cycle __________. Question 19 options: produces NAD makes biochemicals used to make glycogen makes biochemicals used to make triglycerides produces ATP and NADH produces NADP

produces ATP and NADH

What drives the rotation of the F1 head of ATP synthase? Question 20 options: proton movement from the cytoplasm to the intermembrane space ATP hydrolysis proton movement from intermembrane space to the matrix ATP condensation proton movement from the matrix to the intermembrane space

proton movement from intermembrane space to the matrix