Question 1

List the lipid components of cellular membranes.

Accepted Answer

phospholip

Question 2

A phospholipid molecule in a membrane can:

Accepted Answer

A) spin (rotate around its vertical axis). 
B) move side to side (lateral movement). 
C) flip (rotate between the two halves of the bilayer). 
D) both spin (rotate around its vertical axis)and move side to side (lateral movement). 
A) spin (rotate around its vertical axis). 
B) move side to side (lateral movement). 
C) flip (rotate between the two halves of the bilayer). 
D) both spin (rotate around its vertical axis)and move side to side (lateral movement).

Question 3

During the translation of mRNA molecules, the new polypeptides are often directed to specific parts of the cell by the presence or absence of short sequences of amino acids called signal peptides. Which of the following would you expect to find in the polypeptide that will eventually fold to become a histone protein?

Accepted Answer

A) no signal peptide 
B) an amino terminal signal peptide 
C) an internal signal peptide 
D) a signal anchor peptide 
A) no signal peptide 
B) an amino terminal signal peptide 
C) an internal signal peptide 
D) a signal anchor peptide

Question 4

How is a carrier protein different from a channel protein?

Accepted Answer

A) Carrier proteins use ATP, but channel proteins do not. 
B) Carrier proteins undergo conformational change so that they are open alternately to one side of the membrane or the other. 
C) Transport through carrier proteins depends on concentration gradients, but transport through channel proteins does not. 
D) Transport through a carrier does not depend on the random motion of molecules. 
A) Carrier proteins use ATP, but channel proteins do not. 
B) Carrier proteins undergo conformational change so that they are open alternately to one side of the membrane or the other. 
C) Transport through carrier proteins depends on concentration gradients, but transport through channel proteins does not. 
D) Transport through a carrier does not depend on the random motion of molecules.

Question 5

Which one of the following is MOST closely related to archaea?

Accepted Answer

A) eukaryotes 
B) bacteria 
C) both eukaryotes and bacteria 
D) neither eukaryotes nor bacteria 
A) eukaryotes 
B) bacteria 
C) both eukaryotes and bacteria 
D) neither eukaryotes nor bacteria

Question 6

You are investigating a particular cell type, and you notice that a protein normally found in the lysosome ends up being secreted out of the cell. This appears to be the only thing wrong with these cells. Suggest a defect that could explain this observation.

Accepted Answer

One of the signal se

Question 7

A spontaneously generated enclosed bilayer structure is called a(n) _____.

Accepted Answer

The answer of A spontaneously generated enclosed bilayer structure is...

Question 8

What would be the outcome if the pump protein shown in Fig. 5.13a instead acted as a carrier that allowed protons to move from the extracellular fluid into the cytoplasm?

Accepted Answer

A) The proton electrochemical gradient would be reversed. 
B) ATP could be synthesized from ADP + Pi. 
C) The number of protons on either side of the membrane would equalize. 
D) ATP could be synthesized from ADP + Pi and the number of protons on either side of the membrane would equalize. 
A) The proton electrochemical gradient would be reversed. 
B) ATP could be synthesized from ADP + Pi. 
C) The number of protons on either side of the membrane would equalize. 
D) ATP could be synthesized from ADP + Pi and the number of protons on either side of the membrane would equalize.

Question 9

The beaker in the illustration below contains two solutions of salt with different concentrations (measured by molarity, M). The two solutions are separated by a membrane that is permeable to both salt and water.

Which of the following will occur in this container?

Accepted Answer

A) Diffusion of water from B to A and of salt from A to B. 
B) Net diffusion of water across the membrane, but not of salt. 
C) Diffusion of salt across the membrane, but not of water. 
D) Net diffusion of salt from B to A, but no net diffusion of water. 
A) Diffusion of water from B to A and of salt from A to B. 
B) Net diffusion of water across the membrane, but not of salt. 
C) Diffusion of salt across the membrane, but not of water. 
D) Net diffusion of salt from B to A, but no net diffusion of water.

Question 10

Individuals with a condition known as exercise intolerance suffer extreme fatigue from minimal exertion. Defects in which of the following structures are MOST likely responsible for this condition?

Accepted Answer

A) mitochondria 
B) ribosomes 
C) endoplasmic reticulum 
D) Golgi apparatus 
E) lysosome 
A) mitochondria 
B) ribosomes 
C) endoplasmic reticulum 
D) Golgi apparatus 
E) lysosome

Question 11

Which of the following is a pigment associated with chloroplasts that plays a role in energy harvesting?

Accepted Answer

A) thylakoid 
B) melanin 
C) fibril 
D) chlorophyll 
E) ATP 
A) thylakoid 
B) melanin 
C) fibril 
D) chlorophyll 
E) ATP

Question 12

The random movement of molecules is referred to as:

Accepted Answer

A) transport. 
B) osmosis. 
C) diffusion. 
D) All of these choices are correct. 
A) transport. 
B) osmosis. 
C) diffusion. 
D) All of these choices are correct.

Question 13

A beaker contains two solutions of salt dissolved in water. The two solutions have different concentrations (measured by molarity, M) and are separated by a membrane that is permeable to both salt and water.   Which of the following statements is TRUE?

Accepted Answer

A) Side A is hypotonic relative to side B. 
B) Side A is isotonic relative to side B. 
C) Side A is hypertonic relative to side B. 
A) Side A is hypotonic relative to side B. 
B) Side A is isotonic relative to side B. 
C) Side A is hypertonic relative to side B.

Question 14

Mitochondria use _____ and _____ to generate ATP for use by the cell.

Accepted Answer

A) pyruvate derived from sugar; oxygen 
B) sunlight; carbon dioxide 
C) pyruvate derived from sugar; carbon dioxide 
D) sunlight; oxygen 
A) pyruvate derived from sugar; oxygen 
B) sunlight; carbon dioxide 
C) pyruvate derived from sugar; carbon dioxide 
D) sunlight; oxygen

Question 15

Which of the following statements is TRUE regarding chloroplasts?

Accepted Answer

A) Unlike mitochondria, chloroplasts only contain an outer (and not an inner)membrane. 
B) Chloroplasts utilize O2 as a reactant and do not produce O2 as a waste product. 
C) Chloroplasts release CO2 as a waste product. 
D) Chloroplasts are sites of cellular respiration. 
E) None of the answer options is correct. 
A) Unlike mitochondria, chloroplasts only contain an outer (and not an inner)membrane. 
B) Chloroplasts utilize O2 as a reactant and do not produce O2 as a waste product. 
C) Chloroplasts release CO2 as a waste product. 
D) Chloroplasts are sites of cellular respiration. 
E) None of the answer options is correct.

Question 16

Some individuals with defective mitochondria in their muscles are extremely limited in their ability to exercise. Muscle biopsy, followed by microscopic examination of the mitochondria, reveals that the mitochondria are of normal size, but their inner membranes are not as convoluted as normal mitochondria. How could this mitochondrial defect cause the described symptoms in these individuals?

Accepted Answer

Since the inner membranes of the mitocho

Question 17

Which of the following is TRUE of lysosomes?

Accepted Answer

A) The pH is often higher inside the lysosome than in the cytoplasm. 
B) The concentration of protons in the lysosome is often higher than in the cytoplasm. 
C) Proton pumps are sometimes found in the lysosomal membranes. 
D) Lysosomes fuse with other vesicles that contain macromolecules targeted for breakdown. 
E) Lysosomal membranes often contain proteins that transport amino acids, simple sugars, and nucleotides. 
A) The pH is often higher inside the lysosome than in the cytoplasm. 
B) The concentration of protons in the lysosome is often higher than in the cytoplasm. 
C) Proton pumps are sometimes found in the lysosomal membranes. 
D) Lysosomes fuse with other vesicles that contain macromolecules targeted for breakdown. 
E) Lysosomal membranes often contain proteins that transport amino acids, simple sugars, and nucleotides.

Question 18

Why does a phospholipid on the cytoplasmic side of the cell membrane rarely flip to the extracellular side if both environments are polar?

Accepted Answer

A) The polar head group cannot pass through the nonpolar interior. 
B) The two sides have different functions and thus the phospholipid would not function properly. 
C) The cytoplasmic phospholipid is too big to pass through the membrane. 
D) The cholesterol does not allow lipids to move. 
A) The polar head group cannot pass through the nonpolar interior. 
B) The two sides have different functions and thus the phospholipid would not function properly. 
C) The cytoplasmic phospholipid is too big to pass through the membrane. 
D) The cholesterol does not allow lipids to move.

Question 19

Imagine a cell that has a membrane composed mostly of lipids with saturated fatty acid tails, and that this membrane also has low cholesterol content. What are the characteristics of this cell membrane?

Accepted Answer

A) The lipids would be able to easily transition between the inner and outer layers of the bilayer constituting the cell membrane. 
B) The lipids contained in such a membrane would be highly mobile, and in near constant flux. 
C) Due to its cholesterol content, the cell membrane would remain fluid even at cold temperatures. 
D) The characteristics of this cell membrane will closely mirror those of a membrane composed of only unsaturated fatty acids. 
E) None of the answer options is correct. 
A) The lipids would be able to easily transition between the inner and outer layers of the bilayer constituting the cell membrane. 
B) The lipids contained in such a membrane would be highly mobile, and in near constant flux. 
C) Due to its cholesterol content, the cell membrane would remain fluid even at cold temperatures. 
D) The characteristics of this cell membrane will closely mirror those of a membrane composed of only unsaturated fatty acids. 
E) None of the answer options is correct.

Question 20

Where are lysosomal enzymes synthesized?

Accepted Answer

A) on the rough endoplasmic reticulum 
B) in the cytosol 
C) on the Golgi apparatus 
D) in a vesicle 
A) on the rough endoplasmic reticulum 
B) in the cytosol 
C) on the Golgi apparatus 
D) in a vesicle

Exam 5: Organizing Principles: Lipids, Membranes, and Cell Compartments

List the lipid components of cellular membranes.

A phospholipid molecule in a membrane can:

How is a carrier protein different from a channel protein?

Which one of the following is MOST closely related to archaea?

You are investigating a particular cell type, and you notice that a protein normally found in the lysosome ends up being secreted out of the cell. This appears to be the only thing wrong with these cells. Suggest a defect that could explain this observation.

A spontaneously generated enclosed bilayer structure is called a(n) _____.

What would be the outcome if the pump protein shown in Fig. 5.13a instead acted as a carrier that allowed protons to move from the extracellular fluid into the cytoplasm?

The beaker in the illustration below contains two solutions of salt with different concentrations (measured by molarity, M). The two solutions are separated by a membrane that is permeable to both salt and water. Which of the following will occur in this container?

Individuals with a condition known as exercise intolerance suffer extreme fatigue from minimal exertion. Defects in which of the following structures are MOST likely responsible for this condition?

Which of the following is a pigment associated with chloroplasts that plays a role in energy harvesting?

The random movement of molecules is referred to as:

A beaker contains two solutions of salt dissolved in water. The two solutions have different concentrations (measured by molarity, M) and are separated by a membrane that is permeable to both salt and water. Which of the following statements is TRUE?

Mitochondria use _____ and _____ to generate ATP for use by the cell.

Which of the following statements is TRUE regarding chloroplasts?

Which of the following is TRUE of lysosomes?

Why does a phospholipid on the cytoplasmic side of the cell membrane rarely flip to the extracellular side if both environments are polar?

Imagine a cell that has a membrane composed mostly of lipids with saturated fatty acid tails, and that this membrane also has low cholesterol content. What are the characteristics of this cell membrane?

Where are lysosomal enzymes synthesized?

Life: Chemical, Cellular, and Evolutionary Foundations

The Molecules of Life

Nucleic Acids and Transcription

Translation and Protein Structure

Making Life Work: Capturing and Using Energy

Cellular Respiration: Harvesting Energy From Carbohydrates and Other Fuel Molecules

Photosynthesis: Using Sunlight to Build Carbohydrates

Cell Signaling

Cell and Tissue Architecture: Cytoskeleton, Cell Junctions, and Extracellular Matrix

Cell Division: Variations, Regulation, and Cancer

Dna Replication and Manipulation

Genomes

Mutation and Dna Repair

Genetic Variation

Mendelian Inheritance

Inheritance of Sex Chromosomes, Linked Genes, and Organelles

The Genetic and Environmental Basis of Complex Traits

Genetic and Epigenetic Regulation

Genes and Development

Evolution: How Genotypes and Phenotypes Change Over Time

Species and Speciation

Evolutionary Patterns: Phylogeny and Fossils

Human Origins and Evolution

Cycling Carbon

Bacteria and Archaea

Eukaryotic Cells: Origins and Diversity

Being Multicellular

Plant Structure and Function: Moving Photosynthesis Onto Land

Plant Reproduction: Finding Mates and Dispersing Young

Plant Growth and Development

Plant Defense: Keeping the World Green

Plant Diversity

Fungi: Structure, Function, and Diversity

Animal Nervous Systems

Animal Sensory Systems and Brain Function

Animal Movement: Muscles and Skeletons

Animal Endocrine Systems

Animal Cardiovascular and Respiratory Systems

Animal Metabolism, Nutrition, and Digestion

Animal Renal Systems: Water and Waste

Animal Reproduction and Development

Animal Immune Systems

Animal Diversity

Animal Behavior

Population Ecology

Species Interactions, Communities, and Ecosystems

Biomes and Global Ecology

The Anthropocene: Humans As a Planetary Force

Filters

Mitochondria use _ and _ to generate ATP for use by the cell.