Cell Biology Exam 1

Front 1

Which of the following are not true of viruses?

Back 1

Viruses have been successfully grown in pure culture in test tubes.

Front 2

Which of the following statements distinguish bacteria from eukaryotes?

Back 2

All of the above: Eukaryotes have a nuclear envelope, a number of chromosomes, complex cytoskeleton, and divide by mitosis. Bacteria have nucleoid, have one chromosome, no cytoskeleton, divide simply.

Front 3

Human Perspective: it has been proposed that the creation of free radicals (namely reactive oxygen species) is a cause of aging due to the damage these species can cause to cellular material. One of the main protectors against free radicals is Super Oxide Dismutase (SOD). How [many isomers of] SOD have been identified and what are their [cellular locations]?

Back 3

There are 3 that have been identified.1.Cytosolic (located in the Cytosol)2.Mitochondrial (located in the Mitochondria)3.Extracellular (located in the Extracellular Matrix)

Front 4

Proteins are described by varying degrees of structure. Which degree of structure refers to [folding of 1 individual complete polypeptide

Back 4

tertiary

Front 5

A change in viral host range: allows the virus to infect cells from a variety of different organs or host species. For ex: rabies pg 24 in the textbook. When the host range changes, there are drastic consequences because the virus is now able to attack other hosts who may not have been affected beforehand. also the 1918 influenza pandemic on pg 25

Back 5

occurs if genes encoding viral attachment proteins mutate.may allow additional species to contract a particular disease.may allow different organs or tissues to become diseased during viral infection.

Front 6

Which dipeptide listed below has the amino acid that makes a [disulfide] bond AND the amino acid that has [hydrogen] for its side chain?

Back 6

cysteine and glycine (CYS-GLY)

Front 7

Of the following functional groups, which would make a carbon-based compound the least polar?

Back 7

Methyl

Front 8

Which of the following acid/base pairs act as natural buffers in living systems?

Back 8

All of these are correct.: H2CO3/HCO3- (regulates pH of blood)H2PO4-/HPO4-2 (regulates pH of fluids within a cell)histidine+/histidine

Front 9

All cells contain organelles

t/f

Back 9

False

Front 10

Which is unique to RNA?

Back 10

Uracil

Front 11

Which best describes a general phospholipid in a plasma membrane

Back 11

glycerol backbone whose hydroxyl groups are covalently bonded to two fatty acids and a phosphate group

Front 12

based on the nature of lipids which of the following peptide sequences would most likely interact with a lipid?

Back 12

ALA-LEU-ILE-PHE all nonpolar

Front 13

Which of the following have been used as evidence that primitive life forms lacked both DNA and enzymes>

Back 13

RNA can both code genetic info and act as a catalyst

Front 14

Cytoplasm has a pH of about 7. What is the concentration in moles/liter of the hydrogen ion?

Back 14

1x10^-7

Front 15

What type of molecule is shown?

Back 15

Cholesterol

Front 16

Proteins are macromolecular structures take on their higher order structures?

Back 16

All of the above

Front 17

ATP is from which general category of biomolecules?

Back 17

Nucleotides

Front 18

if the ambient temperature around the cell begins to increase how could the cell adjust the plasm membrane>?

Back 18

Add cholesterol and remove double bonds from phospholipids

Front 19

These proteins have domains that protrude from both the extracellular and cytoplasmic sides of membrane

Back 19

integral proteins

Front 20

These proteins are located on either side of the membrane and are covalently situated in the bilayer

Back 20

lipid anchored proteins

Front 21

These proteins are located outside the bilayer

Back 21

peripheral membrane proteins

Front 22

these proteins form a fibrillary network that can act as a support or skeleton for the plasma membrane

Back 22

peripheral membrane proteins

Front 23

What is the best description of the transition temperature in a plasma membrane

Back 23

Where the bilayer changes; a lipid converted from a liquid crystalline phase to a frozen crystalline gel where the movement of the phospholipid is restricted

Front 24

Which of the following statements is true of the sodium potassium pump

Back 24

the sodium pump is electrogenic

Front 25

The ratio of lipid to protein in a plasma membrane is always 3:2 T/F?

Back 25

False

Front 26

The 7 typical membrane functions

Back 26

compartmentalization

scaffold for biochemical activities

selective permeable barrier

transporting solutes

responding to external stimuli

intercellular interaction

energy transduction

Front 27

Which of the following is not found in a eukaryotic voltaqge gated K+ channel

Back 27

Trans membrane domains

Front 28

Which of the following features is not one of the major types of transportation across cell membranes

Back 28

diffusion

Front 29

Which of the following is an example of active transport across the plasma membrane?

Back 29

sodium potassium transporter

Front 30

Which of the following best describes a cerebroside found in the plasma membrane?

Back 30

consists of a fatty acid linked to a carbohydrate

Front 31

consider an ion channel that only moves ions when a ligand is bound to the receptor, what type of gating is this

Back 31

ligand gated ion channels

Front 32

Reactions that release energy are exergonic have a delta g that is....

Back 32

less than 0

Front 33

given the following statements as true

Back 33

Enzymes an only transport energy, activation E depends on reaction mechanism utilized, enzymes stabilize transition states

Front 34

which of the following methods can enzymes use to promote reaction?

Back 34

All of the above

Front 35

Does [pH /temperature ]have any effect on enzymatic activity

Back 35

yes, enzyme amino acid side chains have ionizable groups, changing charges, and pH influences making it more reactiveAlso enzymes are proteins so they will denaturize at higher than their optimal temperaturesAll enzymes have an optimum pH level at which they operate best. Extreme changes in pH can cause enzymes to denature and permanently lose their function.

Front 36

When examining enzyme kinetics, what does the [Michaelis Constant Km] represent?

Back 36

Assuming HIDDEN is Km, represents amount of substrate needed to achieve ½ maximal enzymatic rate(½ Vmax).The amount of substrate needed to achieve ½ maximal enzymatic rate.nd KM can be calculated

Front 37

What is the KM in the control experiment?

Back 37

Km = ( Vmax([S] / (V)) ) - [S] = 100 x (20/28.57) - 20 = 50

Front 38

What is the KM in the experiment with the drug added?

Back 38

Km = ( Vmax([S] / (V)) ) - [S] = 100 x (20/25) - 20 = 60

Front 39

Was the drug a successful inhibitor

Back 39

yes

Front 40

[glycolysis] is a(n) _____ pathway that releases energy, [gluconeogenesis] is a(n) _____ pathway that creates material.

Back 40

Catabolic, anabolic

Front 41

Consider glycolysis how many moles of ATP per mol of glucose converted fully to pyruvate are needed? ]

Back 41

2 mol are needed

Front 42

How many moles of ATP are created per mole of glucose converted fully to pyruvate?

Back 42

4

Front 43

Which of the following statements does not apply to facilitated diffusion?

Back 43

transporters require ATP or coupled energy releasing system to function

Front 44

Looking at the activity profile of an enzyme you notice that upon addition of drug the Vmax changes from 100M/sec to 80 M/sec and the Km remains the same at 20 M. Which of the following conclusions is reasonable?

Back 44

the inhibitor will likely continue to be effective even if substrate concentration increases

Front 45

If a cell is placed into a [HIDDEN] solution what would happen?

Back 45

Hypotonic - water moves net inward

Hypertonic - water moves net outwardIsotonic - No net movement

Hypotonic- Net water Gain cells SWELLS and may lyse (turgid)

Hypertonic- Net water Loss cell SHRINKS- plasmolysis occurs (plasmolysis)

Isotonic - No net Loss or Gain.

Front 46

Reactions that require energy are called endergonic and has a delta G that is

Back 46

positive

Front 47

Which of the following is not a reason for cells to have compartmentalization

Back 47

Well here are the reasons why they do have compartmentalization:-so they can perform specialized activities without interference-Because certain activities in the cell may be dangerous, ex. lysosomes: digestion should be limited to a specific part of the cell so compartmentalization aids in restricting it-also makes it easier for the substrate to find its counterpart

Front 48

Given the following information determine if the pathway A B C D is [HIDDEN]. is it asking if its positive or negative? or spontaneous or nonspontaneous

Back 48

I’m assuming we add all of these together and find the overall delta G to determine if the reaction is spontaneous, non spontaneous, or at equilibrium.If it's negative is spontaneous (Favorable)positive nonspontaneous (Unfavorable)zero is equilibrium.Therefore, the overall reaction is