Biochem 3: I have no idea what's going on and at this point I'm too afraid to ask

which of the following are CORRECT statements?

a. p53 is an example of an oncogene

b. when the Her2 receptor is mutated to an oncogene it is known as Neu

c. oncogenes are derived from cellular homologs known as proto-oncogenes

d. ALL is caused by the formation of BCR-ABL fusion gene

b. when the Her2 receptor is mutated to an oncogene it is known as Neu

c. oncogenes are derived from cellular homologs known as proto-oncogenes

A ___________ mutation is a type of DNA that results in a single amino acid change

a. translocation

b. nonsense

c. silent

d. missense

e. all of the above

f. none of the above

Primary hemostatic refers to which of the following?

a. the extrinsic clotting cascade enhancer

b. vasoconstriction and platelet response

c. the formation of the fibrin clot

d. the intrinsic clotting cascade

a "silent" mutation can occur because of which of the following?

a. Comma-less reading of the mRNA

b. DNA double strand break repair by excision-repair

c. Degenerate nature of the genetic code

d. Universal nature of the genetic code

degenerate nature of the genetic code

Which of the following are CORRECT. Cranial neural crest cells: (select all that apply)

a. are a population of cells the originate from junction between surface ectoderm and the folding neural tube

b. arise via a process known as mesenchymal to epithelial transformation

c. have fates that are specified by their anterior-posterior position (rhombomere of origin) in the hindbrain

d. give rise to the enamel and dentin of developing teeth

a. are a population of cells the originate from junction between surface ectoderm and the folding neural tube

c. have fates that are specified by their anterior-posterior position (rhombomere of origin) in the hindbrain

which for the following are CORRECT. The node...

a. establishes molecular asymmetry that is then converted to symmetric genesis.

b. specifies the fate of the mesoderm as it is formed.

c. acts as a signaling center during gastrulation.

d. has mechanosensory cilia.

b. specifies the fate of the mesoderm as it is formed.

c. acts as a signaling center during gastrulation.

which of the following associations are CORRECT? (select all that apply)

a. G pairs with C

b. G pairs with T

c. A pairs with T

d. A pairs with G

a. G pairs with C

c. A pairs with T

which transcription factors bind to DNA, they do so ny which of the following mechanisms?

a. amino acid side chains interacting with hydrogen atoms and methyl groups in the major and minor groves of

the DNA

b. binding primarily in the major groove

c. forming a triple helix with the DNA

d. complementary pairing with the nucleotide sequence of the promoter site in the DNA

b. binding primarily in the major groove

how do transcription factors bind to the proper site in DNA

a. Complementary pairing with the nucleotide sequence of the promoter site in the DNA

b. Amino acid side chains interacting with hydrogen atoms and methyl groups in the major and minor grooves

c. Binding only to the major groove

d. Forming a triple helix with the DNA

b. Amino acid side chains interacting with hydrogen atoms and methyl groups in the major and minor grooves

c. Binding only to the major groove

(he accepted both of these answers last year, unsure about the correct answer or if it would be on this exam tbh)

Which of the following statements about DNA replication are CORRECT? (select all that apply)

a. Lagging strand DNA fragments are called "Okazaki fragments"

b. In prokaryotic organisms RNA is NOT used as an intermediary step in protein production

c. Lagging strand DNA synthesis begins with the synthesis of a short RNA primer by DNA primase

d. Genes tend to be in AT rich regions in the DNA

a. Lagging strand DNA fragments are called "Okazaki fragments"

c. Lagging strand DNA synthesis begins with the synthesis of a short RNA primer by DNA primase

Which of the following genes are transcribed by RNA Polymerase II? (Select all that apply)

a. A. protein coding genes

b. B. rRNA genes (pol I)

c. C. tRNA genes (pol III)

d. D. microRNA genes

a. A. protein coding genes

d. D. microRNA genes

Which of the following activity is PERFORMED by clusters of HOX genes (select all that apply):

a. are expressed in a manner that is out of order with respect to their position on the chromosome

b. underpin the establishment of tissue patterning via inductive signaling

c. uniquely specify the identity of head structures

d. determine regional identity in the body plan

b. underpin the establishment of tissue patterning via inductive signaling

d. determine regional identity in the body plan

Inductive signaling involves which of the following?

a. cell signaling cascades

b. ability to act over great distance

c. a starting point of a cell or cell cluster

d. All of the above

e. None of the above

d. all of the above

Which of the following statements is INCORRECT?

a. Wee1 kinase inhibits the activity of the cyclin-Cdk

b. The concentrations of the cyclin proteins are induced to promote transitions through the cell cycle

c. The concentrations of the Cdk proteins oscillate during the cell cycle

d. Ubiquitylation of cyclins leads to their degradation in the proteasome

c. The concentrations of the Cdk proteins oscillate during the cell cycle

In order for a Cdk to become fully activated which of the following must occur (select all that apply)?

a. The Cdk T loop threonine must be phosphorylated by CAK

b. The Cdk subunit must be phosphorylated by Wee1 kinase

c. It must bind to itself

d. It must bind to the proper cyclin

a. The Cdk T loop threonine must be phosphorylated by CAK

d. It must bind to the proper cyclin

The pre replicative complex is altered by which of the following to result in the formation of the preinitiation complex?

a. G1-S-Cdk activation

b. S-Cdk activation

c. M-Cdk activation

d. APC/C

S-Cdk activation

Which of the following statements regarding TELOPHASE is CORRECT?

a. The mitotic spindles assemble between the two centrosomes

b. The kinetochore microtubules get shorter

c. The daughter chromosomes arrive at the spindle poles

d. The chromosomes are aligned at the equator

The daughter chromosomes arrive at the spindle poles

Once the cell cycle begins, which checkpoint controls the cell entry into mitosis?

a. APC/C

b. G1/S

c. Late G1

d. G2/M

G2/M

Which of the following is/are important features of the checkpoint control system?

a. cyclical proteolytic events

b. transcriptional regulation

c. cyclically activated cyclin-dependent protein kinases

d. All of the above

e. None of the above

d. All of the above

Which of the following is/are a key function(s) of the active G1-Cdk ?

a. induction of myc gene expression

b. breakdown of the cohesin complex by activating separase

c. phosphorylation of Rb protein

d. All of the above

e. None of the above

c. phosphorylation of Rb protein

A phosphorylation site common to many different proteins would best be described as an example of what?:

a. Motif

b. Secondary structure

c. Domain

d. Quaternary structure

a. Motif (sequences of aa) <-- CORRECT

b. Secondary structure

c. Domain (structural entity, can built from motif(s)

d. Quaternary structure

A sarcoma is derived from which type of normal cell?

a. Lymphatic tissue

b. White blood cells

c. Epithelial cells

d. Muscle cells

muscle cells

A normal, stable and active p53 protein is important for regulating which of the following?

a. apoptosis

b. cell senescence

c. cell cycle arrest

d. All of the above

e. None of the above

All of the above

The SC protein complex is responsible for facilitating the proteasomal degredation of which of the following?

a. Rb protein

b. securin protein

c. Cdk inhibitor proteins (CKls)

d. p53 protein

c. Cdk inhibitor proteins (CKls)

Aneuploidy occurs as a result of which of the following?

a. Dispermy

b. Failure of meiosis in a germ cell

c. Failure of the first cleavage division

d. Nondisjunction during meiosis

d. Nondisjunction during meiosis

A patient with osteogenesis imperfecta is also at risk for which of the following?

a. Dentinogenesis imperfecta Type I

b. Dentinogenesis imperfecta Type II

c. Dentinogenesis imperfecta Type III

d. Amelogenesis imperfecta

a. Dentinogenesis imperfecta Type I

Which of the following statements are CORRECT?

a. While tooth impaction is fairly common in individuals with supernumerary teeth, multiple impacted teeth is rare

b. A gain-of-function mutation in a gene results in an increased or abnormal function of the protein

c. Amelogenesis imperfecta can affect both the primary and permanent teeth

d. All of the above

e. None of the above

d. All of the above

the _____________ is what gives a protein its unique characteristics

variable side chain group

blood flow at a wound site would be expected to _______ by the action of _______

Decrease; serotonin

Which of the following statements regarding cell adhesion is/are correct?

a. Association of ligands with adhesion receptors can

activate intracellular signaling pathways

b. Many adhesion proteins bind one main ligand, and many

ligands bind a single type of receptor

c. Cells modulate adhesion by controlling the surface

density, state of aggregation, and state of activation of

their adhesion receptors

d. All of the above

e. None of the above

all of the above

From a clinical perspective, prothrombin time measures effectiveness of the extrinsic pathway

T/F

TRUE

warfarin prevents the ______________ reaction of key clotting factors

gamma-carboxylation

from a clinical perspective, heparin treatment inhibits the intrinsic pathway and prolongs the aPTT (activated partial thromboplastin time) in patients

t/f

TRUE

heparin is a blood thinner/anticoagulant

- aPTT measures effectiveness of intrinsic and common pathway -- also monitor's patient response to heparin therapy

from a clinical perspective, factor VIII is reduced in patients with Christmas disease

t/f

FALSE

factor IX is reduced in Christmas, Hem. B. Factor VIII is reduced in hemophilia (A)

(Ate = 8)

primary hemostasis refers to which of the following?

a. the extrinsic clotting cascade

b. vasoconstriction and platelet response

c. the formation of the fibrin clot

d. the intrinsic clotting cascade

vasoconstriction and platelet response

from a clinical perspective, dental extractions should not be performed in patients with platelet count level below 50,000 per microliter of blood

t/f

TRUE

from a clinical perspective, idiopathic thrombocytopenia purpura typically causes a prolonged coagulation time

t/f

FALSE

ITP is caused by increasing platelet destruction, leads to increased bleeding tendency, but does not affect coagulation pathway. Platelet function defect only.

which of the following cells would participate in the innate immune system?

a. neutrophils

b. b cells

c. macrophages

d. t cells

e. plasma cells

neutrophils and macrophages

**Which of the following are correct pairs?

a. DNA: deoxyribonucleotide

b. S phase: DNA replication

c. RNA: thymine

d. Nucleosome: histones

a. DNA: deoxyribonucleotide

b. S phase: DNA replication

d. Nucleosome: histones

euchromatin is a more _________ structure and transcriptionally _______. Heterochromatin is more ____________ and _____________ transcriptionally active.

euchromatin is a more RELAXED structure and transcriptionally ACTIVE. Heterochromatin is more CONDENSED and GENERALLY NOT transcriptionally active.

What transcribes most protein coding genes?

RNA polymerase II

DB question, Dr. Wy said "definitely look at these" whatever that means

what is a DNA sequence that recruits DNA-binding proteins which increase RNA production from a gene?

a. open reading from

b. enhancer elements

c. silencer elements

d. repressor element

enhancer elements

DB Comment

Which of the following is a common covalent modification of an amino acid in a histone tail?

A. acetylation of methionine

B. phosphorylation of tyrosine

C. methylation of lysine

D. acetylation of serine

methylation of lysine

*DB comment, Dr. Wy said "Definitely review what the potential effects of methylation are!"

Which of the following types of DNA damage presents a greater challenge for cellular repair mechanisms?

A. Single-strand break

B. Double-strand break

double stranded break

DB comment

how prevalent is hypodontia worldwide?

6.4%

*DB comment, Dr. Wy said, "Recalling this for dentistry is probably a really good idea and knowing about hypodontia is essential!"

what is defined as a "segment of DNA that is transcribed into

RNA and its associated transcriptional control regions"?

a. Gene

b. siRNA

c. mRNA

d. Protein

Gene

which of the following statements about consensus nuclear hormone

response element sequences are correct?

a. They are bound by receptor monomers

b. They are example of a domain in DNA

c. They are an example of a motif in DNA

d. They are always located near the start site of transcription

They are an example of a motif in DNA

what is the correct order for the steps of translation?

Activation --> initiation --> elongation --> termination

inductive signaling is when a cell or groups of cells secrete factors that influence cells that are far away

t/f

FALSE -- the influence neighboring cells

the major protein involved in the formation of enamel is?

amelogenin

amelogenin has a silent mutation, what will be the consequence?

Nothing, the silent mutation doesn't change the protein function. If the mutation was something other than a silent mutation then the answer would be different.

what is the first checkpoint for the cell cycle?

between G1 and S phase

(this checkpoint asks the question "is the environment favorable for me to divide/undergo DNA synthesis?")

what is the second checkpoint for the cell cycle?

between G2 and M phase

it asks the question "is all DNA replicated properly? And, is the environment favorable for cell division/mitosis?"

what is the third checkpoint in the cell cycle?

in M phase

it asks the question "are all the chromosomes attached to the spindle?"

the concentrations of the different CDKs do not change but the concentrations of the different cyclins do change

t/f

TRUE

CDK requires the binding of cyclin and other specific phosphorylation to become an active enzyme

t/f

TRUE BITCH

CAK phosphorylates the t-loop to move it away from the active site

what is the APC/C and what does it do?

anaphase promoting complex and cyclosome

it initiates the metaphase to anaphase transition in the cell cycle

Which of the following are correct combinations?

a) SCF: ubiquitinates p27 in late G1

b) APC/C: ubiquitinates S- and M- cyclins

c) Wee1: inhibitory kinase that phosphoylates a second site on Cdk that makes the Cdk inactive

d) Cdc25 phosphatase: removes phosphate that Wee1 put on Cdk to make the Cdk active again

e) Degradation of securin: activation of a protease that then separates the sister chromatids adn

unleashes anaphase

f) All of the above

All of the aove

a sigle mutation is sufficient to cause cancer

t/f

FALSE

a single mutation is not enough to cause cancer but a single mutation is sufficient to cause disease

_____, ______, and ________ constitute over 90% of all congenital bleeding disorders

hemophilia A, hemophilia B, and Von Willebrand's disease

in _________ the DNA is broken up into regions or blocks of sequence that will give rise to the protein sequence

eukaryotic organisms

in eukaryotes, one strand of DNA is first copied in a ________ and then the introns are removed by a process called splicing

linear fashion

in eukaryotes, primary transcripts are often spliced in multiple combinations of exons which is called ________

alternative splicing

the human genome is made up of ~__-billion base pairs

3.2 billion