Cell Biology Exam 1 Mehari

Explain in at least 3 sentences. Not more than 6 sentence, to describe the relationship between cells, chromosomes, DNA, RNa, and proteins.

* list your points by number or bullet points

1) the central dogma states that the transfer of info flows from DNA to proteins

2) chromosomes are composed of DNA

3) DNA uses transcription to create complementary RNA strands

4) RNA strand through the process of translation creates a protein

5) proteins are responsible for cell function providing the link between chromosomes and the greater mass of the cell

The cytoskeleton of eukaryotic cells are responsible for directed cell movements. Which of the following make up the cytoskeleton.

Hint: multiple answer question. you will be penalized for selecting the wrong answer

A) intermediate filaments

B) actin filaments

C) intermediate tubules

D) microtubules

intermediate filaments

actin filaments

microtubules

Which of the following statement are true of chloroplast?

Hint: multiple answer question. you will be penalized for selecting the wrong answer

A) chloroplast absorb light and generate oxygen and electrons

B) chloroplasts are present in essentially all eukaryotic cells

C) chloroplasts are thought to have originated from bacteria

D) chloroplasts contain their own DNA

chloroplast absorb light and generate oxygen and electrons

chloroplasts are thought to have originated from bacteria

chloroplasts contain their own DNA

These are all the reasons why arabidopsis has been chosen as a model plant except

A) has one of the largest genome in plant kingdom

B) has relatively small genome

C) the ability to self-fertilize

D) Short generation time

has one of the largest genome in plant kingdom

Mitochondria are thought to have evolved from engulfed aerobic bacteria. Which of the following are evidences that support the theory of endosymbiosis in eukaryotic cells.

Hint: multiple answer question. you will be penalized for selecting the wrong answer

A) Mitochondria possess ribosomes similar in size to bacterial ribosomes

B) mitochondria possess nucleus similar in size to bacterial nucleus

C) mitochondria contains double membranes resembles that of a bacterial double membrane

D) mitochondria contains DNA arranged in circular chromosome

mitochondria contains double membranes resembles that of a bacterial double membrane

mitochondria contains DNA arranged in circular chromosome

Mitochondria possess ribosomes similar in size to bacterial ribosomes

Mitochondria are essentially the same in all eukaryotes, including plants, animals, and fungi

TRUE

FALSE

True

Eukaryotic cells engage in continual endocytosis and exocytosis across their plasma membrane. Why do cells engage in endocytosis

A) to import extracellular materials

B) they use it to communicate with other cells

C) secrete intracellular materials

D) they use it for mating with other similar cells

to import extracellular materials

Within a developed multicellular organism, NOT all cells have the ability to divide

TRUE

FALSE

true

All of the following are advantages of using electron microscope when compared to light microscope EXCEPT

A) they are used to study viruses

B) they are used to visualize ribosomes

C) they are used to study sub-cellular structures

D) they are used to study live cells

they are used to study live cells

In the electron micrograph below, identify the bacterial cell features labeled A to D respectively

A is pointing to a light shaded area in between

A) cytoplasm, cell wall, inner membrane, outer membrane

B) Outer membrane, inner membrane, cell wall, cytoplasm

C) cell wall, inner membrane, cytoplasm, outer membrane

D) outer membrane, cell wall, inner membrane, cytoplasm

cell wall, inner membrane, cytoplasm, outer membrane

The DeltaG of a reaction is -350 kcal/mol. Which of the following can be deduced about the reaction?

A) The reaction will proceed spontaneously under standard conditions

B) the reaction will proceed in the presence of another reaction with a positive DeltaG value

C) none can be deduced based on the presented information

The reaction will proceed spontaneously under standard conditions

What can be said about the molecule present below.

Hint: multiple answer question. you will be penalized for selecting the wrong answer

A) no, it is a plane

B) it belongs to RNA

C) No, its a bird

D) it is a nucleotide

E) it belongs to one of the non-polar amino acids

F) it belongs to DNA

it belongs to RNA

it is a nucleotide

Which of the following are types of interactions that help bring molecules together in cells?

Hint: multiple answer question. you will be penalized for selecting the wrong answer

A) covalent bonds

B) van der Waals attraction

C) Hydrogen bond

D) Ionic Bond

covalent bonds

van der Waals attraction

Hydrogen bond

Ionic Bond

Which of the following is not a characteristics of yeast that made them useful model organisms?

A) unlike other eukaryotes, yeast do not have membrane bound nucleus

B) they can be grown cheaply and quickly

C) they can be haploid or diploid

D) homologs of yeast proteins are found in nearly all eukaryotes

unlike other eukaryotes, yeast do not have membrane bound nucleus

Peptide bond formation between the amino group and the carboxyl group of another results in

A) release of carbonyl group

B) release of carbon dioxide molecules

C) release of water molecules

D) release of amide group

release of water molecules

When comparing liver cells and kidney cells within the same organism, which of the following is the same between the two cells?

A) DNA

B) Lipids

C) RNA

D) Proteins

DNA

You feed 2 glucose molecules to a yeast. Saccharomyces cerevisiae. How many total number of ATP will you expect to recover if the cell decides to ferment the sugars

A) 4

B) 2

C) 76

D) 10

E) 38

4

Which of the following is not correct with respect to the redox pair NAD+/NADH?

A) NADH can accept electrons from an electron transport system

B) the nicotinamide ring is heteroaromatic because it has a non carbon atom is the 4th position

C)The nicotinamide ring is relatively stable aromatic structure

D) The reduced, non aromatic ring of NADH is at a higher energy than the aromatic ring of NAD+

NADH can accept electrons from an electron transport system

Which of the following statements about NADPH and/or NADH is NOT true?

A) NADPH is used primarily in plants

B) NADPH is used in biosynthetic reaction to build energy rich molecules

C) NADH is used by both animals and plants

D) NADH is used in powering the production ATP

NADPH is used primarily in plants

Which of the following is not true of chemiosmosis?

A) it requires oxygen

B) the proton motive force is used to synthesize ATP

C) it produces majority of ATP in a cell

D) ATP synthase generates ATP from ADP and Pi

it requires oxygen

ATP synthesis by chemiosmosis is similar in bacteria, mitochondria, and chloroplasts

TRUE

FALSE

True

The TCA cycle is capable of generating all of the following products from oxidation of each acetyl-CoA molecule EXCEPT

A) One ATP molecule

B) two carbon dioxide molecules

C) two FADH2

D) two water molecules

E) 3 NADH molecules

two water molecules

The enzyme pyruvate kinase catalyzes the conversion of PEP to Pyruvate. The phosphate is transferred to ADP to form ATP. This reaction is an example of

A) ATP synthesis by oxidative phosphorylation

B) ATP synthesis through substrate level phosphorylation

ATP synthesis through substrate level phosphorylation

In brown fat of bears. The following transmembrane proteins are use to produce heat during the cold season

A) F0 complex of ATP synthase

B) uncoupling proteins (UCPs)

C)F1 complex of ATP synthase

D) CoqH2 molecules

uncoupling proteins (UCPs)

Photosynthesis utilizes an electron transport system while fermentation does not utilizes an electron transport system

TRUE

FALSE

True

Fermentation produces more energy than anaerobic Respiration

TRUE

FALSE

False

Production of ATP by ATP synthase directly depends on which of the following factors?

A) electron carrier force

B) Neutron motive force

C) GTP

D) proton motive force

proton motive force

What is the main purpose of Malate-Aspartate shuttle to cells

A) transfer of electrons from cytosolic NADH across the inner mitochondrial matrix

B) transport of Acetyl-CoA form cytoplasm to the mitochondrial matrix

C) transfer of electrons from cytosolic NADH across the inner mitochondrial membrane

D) transfer of electrons from matrix NADH across the inner mitochondrial membrane

transfer of electrons from cytosolic NADH across the inner mitochondrial matrix

Which of the following statements is TRUE to both FADH2 and NADH?

Hint: multiple answer question. you will be penalized for selecting the wrong answer

A) both are electron carriers that power the electron transport system

B) Both have the ability to produce similar amount of ATP

C) Both are products of glycolysis

D) Both are products of TCA

Both are products of TCA

both are electron carriers that power the electron transport system

Both have the ability to produce similar amount of ATP

Which of the following allows the one way movement of electrons from one complex to the next in ETS?

A) decrease in reduction potential from NADH to O2

B) Presence of more protons in the cytosolic side of the membrane

C)Presence of more protons between the inner and outer membrane of mitochondria

D) increase in reduction potential from NADH to O2

increase in reduction potential from NADH to O2

Oxygen is always required for the regeneration of NAD from NADH

TRUE

FALSE

False

Which of the following is NOT a method for controlling protein activity

A) ATP hydrolysis

B) phosphorylation can control protein activity by causing a conformational change

C) proteolysis

D) Catalytic activity of enzymes are often regulated by the product of the reaction

proteolysis

Which of the following does not represent covalent interactions?

A) disulfide formation between two antibody subunits

B) disulfide formation during folding of the newly translated protein

C) hydrogen-bonding between peptide bonds in adjacent strands in a beta sheet

D) peptide bond between two amino acids

hydrogen-bonding between peptide bonds in adjacent strands in a beta sheet

Mutations in the nucleic acid sequence of a gene can sometimes direct the substitution of one amino acid for another in the encoded protein. which amino acid substitution would be most likely to severely disrupt the normal structure of a protein?

A) tyrosine to tryptophan

B) Alanine to glycine

C) leucine to isoleucine

D) Methionine to Aspartic Acid

tyrosine to tryptophan

Which of the following is NOT TRUE about the enzyme lysozyme

A) its activity increases with increase in substrate concentration

B) it involves addition of water molecule

C) catalyses the cutting of polysaccharide substrate molecule

D) It involves removal of water molecules

it involves removal of water molecule

Which of the following is NOT a characteristic of hemoglobin molecule

A) its ability to deliver oxygen to muscle cells depends on the concentration of carbon dioxide

B) its function depend on the chemical property of the heme group

C) its ability to deliver oxygen to muscle cells depends on pH

D) its is made of one large protein subunit

its is made of one large protein subunit

Which of the following determine how a protein will fold?

A) peptide bond structure

B) amino acid sequence

C) chaperone

D) Chaperones and peptide bond structure

amino acid sequence

A competitive inhibitor bound to an enzyme can be overcome by increasing the substrate concentration

TRUE

FALSE

True

Which parts of amino acids are involved in a peptide bond?

A) phosphate of one amino acid and sugar of the other

B) carbonyl group of one amino acid and side chain of the other

C) Amino group of one amino acid and carboxyl group of the other

D) Carboxylic acid of one amino acid and fatty acids of the other

Amino group of one amino acid and carboxyl group of the other

Beta sheets of proteins

A) are strands of polypeptide chains are held together by hydrogen-bonding between peptide bonds in adjacent strands

B) are formed by hydrogen bonding of the N-H of every peptide bond to the C=O of a neighboring peptide bond four amino acids away

C) are the major components of membrane-bound proteins across the lipid bilayer

D) can be either right-handed or left-handed

are strands of polypeptide chains are held together by hydrogen-bonding between peptide bonds in adjacent strands

Which statement is TRUE about the removal of terminal phosphate from ATP?

A) the reaction is a dehydration reaction

B) the reaction is associated with positive charge in delta G

C) the reaction is associated with a negative charge in Delta G

D) the reaction in a condensation reaction

the reaction is associated with a negative charge in Delta G

Which of the following is NOT a function of an enzyme?

A) speed up a reaction by lowering activation energy

B) bring substrates into close proximity

C) Couple favorable and unfavorable chemical reactions

D) speed up reaction by increasing the activation energy

speed up reaction by increasing the activation energy

What determines the specificity an antibody has for its antigen?

A) polypeptide loops in its variable domains

B) polypeptide loops of its heavy chains

C) polypeptide loops in its constant domains

D) polypeptide loops of its light chains

polypeptide loops in its variable domains

Which of the following technique would you use to separate two proteins with the same size but different isoelectric point

A) ion-exchange chromatography

B) two-dimensional PAGE

C) antibody-affinity chromatography

D) SDS-PAGE

two-dimensional PAGE

You purified a protein complex with multiple subunits band together by disulfide bond. Which of the following chemicals would you use to separate the subunits before loading it to polyacrylamide gel electrophoresis

A) mercaptoethanol

B) sodium dodecyl sulfate

C) weak base

D) Weak acid

mercaptoethanol

Which of the following can be used for separating different proteins within a sample.

Hint: multiple answer question. you will be penalized for selecting the wrong answer

A) mass spectrometry

B) liquid chromatography

C) x-ray crystallography

D) SDS-PAGE

SDS-PAGE

liquid chromatography

You are running an experiment to mutate an enzyme in order to increase the enzyme's ability to bind to its substrate. Using the graph as a comparison, what effect would the mutant version of the enzyme likely have on the Km?

A) The Km would move to the right (increased)

B) The Km would not change at all (no Effect)

C) The KM would move to the right initially but eventually move to the left

D) The Km would move to the left (decrease)

The Km would move to the left (decrease)

Rank the following events in chronological order based on the figure below

1) eukaryotic and archaea diverged

2) eukaryote acquired chloroplast

3) bacteria and archaea diverged

4) eukaryotes acquired mitochondria

A) 1 2 3 4

B) 4 3 2 1

C) 1 3 4 2

D) 3 1 4 2

3 1 4 2

Explain in at least 3 sentences, but not more than 6 sentences, how regulatory GTP binding protein can be responsible for human cancer

*list your explanation by number or bullet point

* mention at least one example of a protein regulated by GTP-binding

1) an aggregation of misfolded protein structures can lead to the development of cancer and neurodegenerative disorders

2) GTP-binding proteins, in the presence of a plethora of energy will not stop folding the proteins, which can lead to misfolding and the harmful aggregations aforementioned

3) GTP-binding proteins are not directly related in folding of RAS protein