Quals

Question 1

Define genome

Answer 1

The set of different DNA molecules in an organism, cell, or DNA virus, or of RNA molecules in an RNA virus

Question 2

What is the advantage of a DNA genome over and RNA genome?

Answer 2

DNA’s antiparallel nature allows it to copy itself, DNA is also more stable than SS RNA

Question 3

How can RNA be grouped into 2 broad categories?

Answer 3

1. mRNA

2. noncoding RNA

Question 4

What is the central dogma? Are there any exceptions to this rule?

Answer 4

DNA –> RNA –> Protein

Retroviruses, retrotransposons, telomerase

Question 5

Chemically, what’s different between DNA and RNA

Answer 5

RNA has OH (hydroxyl) at 2’ of its sugar, and DNA doesn’t.

Question 6

What’s the differnce between a nuceloside and a nucleotide?

Answer 6

Nucleoside = base + sugar
Nucleotide = base + sugar + phosphate

Question 7

What type of bond attaches a base to a sugar?

Answer 7

Covalent, N-glycosidic bond

Question 8

What kind of reaction occurs between the amino and carboxyl groups of amino acids to form polypeptides?

Answer 8

Condensation

Question 9

What is a major property of DNA replication?

HINT: semi _____ and semi _____

Answer 9

It is semi-conservative, and semi-discontinuous

Question 10

How many nulceotides are Okazaki fragments?

Answer 10

100-1000 nts

Question 11

DNA polymerase ___ synthesizes the ____ strand of DNA and DNA polymerase __ synthesizes the ____ strand of DNA. What is the property of these polymerases that gives them such a low error rate?

Answer 11

epsilon = leading
delta = lagging

3’ –> 5’ exonuclease

Question 12

Initiation of DNA replication requires DNA polymerase ____. What accounts for proofreading this polymerase?

Answer 12

Initiation = alpha

Proofreading = DNA polymerase delta

Question 13

Mitochondrial DNA is synthesized by DNA polymerase ____?

Answer 13

gamma

Question 14

RNA is usually single stranded, are there ever times where it is double stranded?

Answer 14

Some viral genomes, hairpins formed in tRNAs, regulatory ncRNAs in the genome.

Question 15

the virus is a (+)-virus if ________, and the virus is a (−)-virus

Answer 15

if the polypeptide-making RNA has the same sense as the genome

if instead it is complementary in sequence to the genome

Question 16

How many base pairs of DNA per alpha helical turn?

Answer 16

10

Question 17

In transcription, the antisense strand is the ____ strand, and the sense strand is the _____ strand.

Options: template, non-template

Answer 17

antisense= template
sense = non-template

Question 18

When referring to subunits (i.e. 50S, 5S, 60S, 40S subunits), what is S?

Answer 18

Svedberg units (sedimentation)

Question 19

Define enhancer

Define silencer

Answer 19

a cluster of cis-acting short sequence elements that can enhance the transcriptional activity of a small subset of genes

a cluster of cis-acting short sequence elements that can depress the transcriptional activity of a small subset of genes

Question 20

What types of transcripts are the exception to being polyA’d?

Answer 20

Histone transcripts

Question 21

What sequence addition is required for tRNA maturity?

Answer 21

CCA to the 3’ end.

Question 22

Which rRNA is not transcribed by RNApol1?

Answer 22

5S is transcribed by RNApol(III)

Question 23

Chromosomally, where are rRNA genes found?

Answer 23

tandemly repeated about 30–40 times at
the nucleolar organizer regions on the short arms of each of the five human acrocentric
chromosomes (13, 14, 15, 21, and 22)

Question 24

Name the 4 arms of a tRNA

Answer 24

1. Dihydrouridine (D arm)
2. Anticodon arm
3. Psuedouridine (TψC arm)
4. Acceptor arm

Question 25

What does the mRNA modification 6-methyladenosine signal?

Answer 25

regulating alternative splicing, and the same modification is used to signal that precursor miRNAs are ready to be processed into miRNAs

Question 26

What are the functions of the 5 and 3' UTRs?

Answer 26

assist in binding and stabilizing the mRNA on the ribosomes, and promote efficient translation

Question 27

An amino acid–tRNA | complex is known as an _____.

Answer 27

aminoacyl tRNA

Question 28

What is the translation initiation consensus sequence called?

Answer 28

Kozak sequence

Question 29

In the large ribosomal subunit, which subunit is responsible for peptidyl transferase activity?

Answer 29

28S

Question 30

Glycosylation occurs mainly to proteins that _____________.

Answer 30

proteins that are secreted from cells or transported | to lysosomes, the Golgi apparatus, or the plasma membrane are routinely glycosylated

Question 31

What are the 2 major types of glycosylation?

Answer 31

Carbohydrate N-glycosylation involves attaching a carbohydrate group to the nitrogen atom of an asparagine side chain and O-glycosylation entails adding a carbohydrate to the oxygen atom of an OH group carried by the side chains of certain amino acids

Question 32

What is the purpose of adding fatty acyl or prenyl groups to proteins?

Answer 32

Act as membrane anchors

Question 33

What is the purpose of sumoylation?

Answer 33

Sumoylation induces the proteins to change their behavior (via altered binding properties, change of localization within cells, and so on), and is important in regulating certain processes, such as transcription, chromatin structure, DNA repair, protein stability, transport between the nucleus and cytoplasm

Question 34

What is the purpose of ubiquitination?

Answer 34

PRotein degradation

Question 35

What are the three cytoskeleton filaments?

Answer 35

1. Actin Microfilaments 2. Microtubules 3. Intermediate filaments

Question 36

What was the endosymbiont that gave rise to the mitochondrial genome?

Answer 36

α-proteobacterium

Question 37

The default human cell is diploid, which types of cells are nullploid, haploid, or polyploid?

Answer 37

``` Nullploid = erythrocytes, platelets, keratinocytes Haploid = gametes Polyploid = cardiomyocytes, magakaryocytes, hepatocytes, skeletal muscle fibres ```

Question 38

If RBCs don't have nuceli, how come you can extract DNA from blood?

Answer 38

WBCs and other cellular fragments

Question 39

For a chromosome to be copied and transmitted accurately to daughter cells, it requires just three types of structural elements. What are they?

Answer 39

1. Centromere 2. Origins of replication 3. Telomeres

Question 40

What types of DNA sequences are suspected to lead to reproductive isolation of various species?

Answer 40

Centromeric DNA

Question 41

Where is the human origin of replication?

Answer 41

DNA is replicated from multiple initiation sites along each chromosome, with an average of roughly one initiation site per 40–80 kb of DNA. Potentially G rich to form guanine quadruplexes

Question 42

What are the 2 distinct types of heterochromatin?

Answer 42

1. Constitutive (permanent) | 2. Faculative (reversible)

Question 43

What's the vertebrate telomere seuqence?

Answer 43

TTAGGG