Deck 2: Living Cells

Question 1

During exocytosis membrane-bound vesicles migrate from the Golgi apparatus to the __________.

A) Lysosome
B) Smooth endoplasmic reticulum
C) Cell wall
D) Plasma membrane
E) More than one answer is correct

Answer 1

D

Question 2

Notable features of eukaryotes include all of the following except ________.

A) Rapid cell division
B) Larger size
C) A complex internal structure
D) An endomembrane system
E) Organelles

Answer 2

A

Question 3

Gram-negative bacteria lack _________.

A) Cell walls
B) Peptidoglycans in the cell wall
C) An outer coat of lipid bound proteins
D) DNA
E) Carbohydrate containing polymers in the cell wall

Answer 3

E

Question 4

The plasma membrane _________.

A) Provides support
B) Is present only in eukaryotes
C) Controls the flow of substances in and out of the cell
D) Is present only in prokaryotes
E) Both A and C are correct

Question 5

Structural features that make phospholipids suited for their biological role are:

A) A hydrophilic head group
B) Branched carbon chains
C) A hydrophobic group
D) A and C are correct
E) None of the above is true

Question 6

The grainy appearance of prokaryotic cytoplasm is due in part to ________.

A) A large number of ribosomes
B) Plasmids
C) Nucleolus
D) DNA
E) RNA

Question 7

Which of the following types of molecules is not hydrophilic

A) Sodium chloride
B) Glucose
C) Amino acids
D) Fats
E) Both A and B are correct.

Question 8

The basic structure of biological membranes is provided by what class of compounds?

A) Proteins
B) Lipids
C) Carbohydrates
D) Steroids
E) Peptidoglycans

Question 9

Which of the following is not true of the nucleus?

A) It is found in both eukaryotes and prokaryotes
B) It contains the cell's "genetic blueprint"
C) It exerts a profound influence over all cellular metabolic functions
D) It contains chromatin fibers
E) It is bounded by membrane

Question 10

Which of the following statements is not true of the endoplasmic reticulum?

A) It often constitutes more than half of the cell's total membrane
B) It exists in two forms: rough and smooth
C) Rough ER is responsible for protein synthesis
D) Smooth ER is responsible for lipid synthesis
E) Rough ER ribosomes are responsible for biotransformation.

Question 11

Which of the following is not true of eukaryotic ribosomes?

A) They are macromolecular machines
B) They function in the biosynthesis of proteins
C) They contain ribosomal RNA
D) They consist of two unequally sized subunits
E) They are attached to the smooth ER

Question 12

Which of the following statements is not true of the Golgi apparatus?

A) The analogous plant structure is referred to as a dictyosome
B) It has two faces
C) The cisterna or forming face usually projects toward the ER
D) It is involved in the packaging and secretion of cell products
E) It is usually located near the plasma membrane

Question 13

Which of the following statements is not true of the lysosome?

A) It functions in intercellular digestion
B) Both ER and Golgi apparatus are involved in its formation
C) It is capable of degrading most biomolecules
D) It is involved in the packaging and secretion of cell products
E) It is involved in pathological conditions such as gout and rheumatoid arthritis

Question 14

Acid hydrolases are found in ___________.

A) Ribosomes
B) Lysosomes
C) Golgi Apparatus
D) Dictyosomes
E) Smooth ER

Question 15

The main role of peroxisomes is _____________.

A) Anaerobic respiration
B) Aerobic respiration
C) Lipid oxidation
D) Generation and destruction of peroxides
E) Carbohydrate oxidation

Question 16

Biological machines are derived from which class of compounds

A) Fats
B) Proteins
C) Carbohydrates
D) Ribosomes
E) B and C

Question 17

Which of the following organelles is involved in aerobic metabolism?

A) Mitochondria
B) Peroxisomes
C) Glyoxysomes
D) Ribosomes
E) Lysosomes

Question 18

Respiratory assemblies are responsible for the synthesis of ___________.

A) ATP
B) NADH
C) GTP
D) Hydrogen peroxide
E) ADP

Question 19

The two membranes of the mitochondria create two separate compartments called the intermembrane space and the __________.

A) Cristae
B) Matrix
C) Lumen
D) Cisternae
E) Vesicle

Question 20

Which of the following statements is not true of the mitochondrial matrix?

A) It contains enzymes responsible for nucleotide metabolism
B) It contains circular DNA molecules
C) It contains all of the necessary compounds for protein synthesis
D) It has a gel-like consistency
E) It has a high concentration of enzymes and ions

Question 21

The excluded volume of a cell varies between _____ and ______%.

A) 5-10
B) 10-20
C) 20-40
D) 40-50
E) 0-5

Question 22

Plastids are plant structures similar to what organelle found in animals?

A) Ribosomes
B) Leucoplasts
C) Golgi apparatus
D) Peroxisomes
E) None of the above is correct

Question 23

The stroma of plastids is analogous to what structure of mitochondria?

A) Grana
B) Matrix
C) Inner membrane
D) Outer membrane
E) Cisternal space

Question 24

Which of the following help make up the cytoskeleton?

A) Microtubules
B) Microfilaments
C) Intermediate fibers
D) B and C are correct
E) All are correct

Question 25

Mitochondria and _________ consume molecular oxygen.

A) Plastids
B) Ribosomes
C) Peroxisomes
D) Lysosome
E) Golgi apparatus

Question 26

Which of the following is present only in prokaryotic cells?

A) Nucleus
B) Endoplasmic reticulum
C) Plasma membrane
D) Nucleolus
E) None of the above is correct

Question 27

Biotransformation is defined as:

A) The preparation of water-insoluble substances for excretion
B) Oxidation of organic molecules
C) Transformation of food molecules to ATP
D) Reactions occurring within a living system
E) Conversion of harmless compounds to toxins

Question 28

In place of a nucleus a prokaryotic cell has a __________.

A) Mesosome
B) Nucleoid
C) Centrosome
D) Nucleosome
E) Reticulosome

Question 29

Which of the following eukaryotic organelles is a key regulator of apoptosis?

A) Mitochondria
B) Flagella
C) Chloroplasts
D) Cilia
E) Ribosomes

Question 30

Which of the following is not a role of transmembrane proteins?

A) Transport of ions
B) Structural support
C) Transport of nutrients
D) Receptors
E) Enzymes

Question 31

Which of the following is not a membrane protein?

A) Channel protein
B) Carrier protein
C) Receptors
D) Integral proteins
E) Motor proteins

Question 32

Examples of eukaryotic signal molecules are:

A) Neurotransmitters
B) Hormones
C) Cytokines
D) Both A and B are correct
E) All of the above are correct

Question 33

Which of the following is not a phase of the information processing mechanism?

A) Reception
B) Transduction
C) Response
D) Transformation
E) Both A and C are correct

Question 34

Which of the following is not a component of the endomembrane system?

A) Plasma membrane
B) Endoplasmic reticulum
C) Golgi apparatus
D) Lysosomes
E) Ribosomes

Question 35

The carbohydrate coat of a cell is called the:

A) Extracellular matrix
B) Glycocalyx
C) Cell cortex
D) Fibroblast
E) Both A and C are correct

Question 36

The perinuclear space is:

A) The space between the nucleus and the cytoplasm
B) The space between the membranes of the nuclear envelope
C) The space between the nucleus and the nucleous
D) The space between DNA and histones
E) Both A and B are correct

Question 37

Which of the following organelles are involved in autophagy?

A) Mitochondria
B) Lysosomes
C) Chloroplasts
D) Golgi apparatus
E) Both B and C are correct

Question 38

Which of the following molecules is not an example of a type of eukaryotic signal molecule?

A) Neurotransmitter
B) Hormone
C) Cytokinin
D) Endotoxin
E) Both A and B are correct

Question 39

Of the approximately100 trillion cells in the human body how many are actually human cells?

A) All of them
B) 50 Trillion
C) 90 Trillion
D) 10 Trillion
E) 80 Trillion

Question 40

Analysis of the RNA of prokaryotes reveals that there are ______ distinct types of
Prokaryotes.

A) One
B) Two
C) Three
D) Four
E) Five

Question 41

Which of the following are microbiota

A) Bacteria
B) Fungi
C) Archea
D) A and B
E) A, B and C

Question 42

Which of the following are techniques used by the body to protect itself against
Indigenous microbiota

A) Impenetrable epithelial tissue
B) Immune system cells
C) Antimicrobial proteins
D) Beta defensins
E) All of the above

Question 43

Which of the following is a superorganism

A) Streptococcus
B) Lactobacillus
C) Homo sapiens
D) Corynebacterium
E) Klebsiella

Question 44

The endocytic cycle is

A) A means of remodeling plasma membrane
B) A form a signal transduction
C) Cycling of sodium and potassium ions through the cell membrane
D) Continuous recycling of membrane through endocytosis and exocytosis
E) A and D

Question 45

What is an integral protein?

Question 46

What is a peripheral protein?

Question 47

What is a ligand?

Question 48

What is the function of a motor protein?

Question 49

What is meant by the term macromolecular crowding?

Question 50

What is an endotoxin?

Question 51

What is the slime layer?

Question 52

Explain why the term "crowded" rather than "concentrated" is used to describe the densely packed molecules on the interior of living cells?

Question 53

Describe how noncovalent interactions promote the self-assembly of supramolecular structures in living organisms.

Question 54

How do lysosomes participate in the life of the cell?

Question 55

What functions does the cytoskeleton perform in living cells?

Question 56

What roles do plasma membrane proteins play in living cells?

Question 57

What are two essential functions of the nucleus?

Question 58

Describe the functions of the Golgi apparatus.

Question 59

List three environmental signals detected by primary cilia.

Question 60

Describe the function of kinesins and dyneins in intraflagellar transport.

Question 61

Humans have been described as superorganisms consisting of human cells in combination with a larger number of microorganisms. Explain. Is this a symbiotic relationship? What effect can the consumption of antibiotics have on this relationship?

Question 62

Biological membranes are held together by weak noncovalent forces. Why is it important that weak forces hold membranes together? What would happen if membrane structure involved stronger covalent bonding?

Question 63

What effect does macromolecular crowding have on the traditional analysis of reaction rates?

Question 64

Eukaryotic cells are much larger cells than prokaryotic cells. What factors of internal structure make this increase in size possible?

Question 65

Comment on the statement that the cytoplasm is just a soup containing organelles.

Question 66

The interior of living cells is highly organized and this organization is maintained over long periods of time. Entropy, a measure of the disorder or randomness of the system, predicts that highly organized systems should become progressively disorganized. How does a living cell evade entropy?

Question 67

The surface of the eukaryotic cell is coated with carbohydrate groups attached to protein and lipid molecules. What structural feature of the carbohydrate molecule accounts for this phenomenon?

Question 68

Mitochondria are one of many types of organelles. What features of mitochondria argue most strongly for their descent from a free living ancestor?

Question 69

In eukaryotes the DNA remains within the nucleus and RNA, synthesized within the nucleus, is used to transfer information to the rest of the cell. Why use RNA for this purpose and why not just use DNA directly?

Question 70

In density gradient centrifugation the products are removed from the bottom of the centrifuge tube. Why not remove them from the top of the tube?

Question 71

The dimensions of a prokaryotic ribosome are approximately 14 nm x 20 nm. If ribosomes occupy 20% of the volume of a bacterial cell calculate how many ribosomes are in a typical cell such as E. coli. Assume that the shape of a ribosome is approximately that of a cylinder. A typical bacterial cell volume is 1.6 um³.

Question 72

The E. coli cell is 2 $\mu$ m long and 1 $\mu$ m in diameter, while a typical eukaryotic cell is 20 $\mu$ m in diameter. Assuming that the E. coli cell is a perfect cylinder and the eukaryotic cell is a perfect sphere, calculate the surface-to-volume ratio for each cell type [cylinder volume V = $\pi$ r²h; cylinder area A = 2 $\pi$ r² + 2 $\pi$ rh; sphere volume V = 4/3( $\pi$ r³); sphere area 4 $\pi$ r²].What do these numbers tell you about the evolutionary changes that would have to occur to generate an efficient eukaryotic cell considering that most biochemical processes depend on membrane-bound processes.