BIO 202 Midterm 4 Review

Flashcards for BIO 202 Midterm 4, covering topics like enzymes, gene regulation, DNA replication, and molecular biology techniques.

What is the function of kinases and phosphatases?

Kinases catalyze phosphorylation, while phosphatases catalyze removal of phosphate(s). They can function as an on-off switch for various processes through a change in a protein's charge leading to a conformational change.

How does histone acetylation affect histone charge and DNA binding affinity?

Histone acetylation neutralizes positive histone charges and binds to DNA more loosely.

What is likely to have ubiquitin attached to it?

A cyclin protein, that usually acts in G1, in a cell that is in G2.

When does full induction of the lac operon occur?

Lactose levels are high and glucose levels are low.

What is the function of dideoxynucleotides in a Sanger DNA sequencing reaction?

They stop DNA synthesis at certain sites.

Which components of a eukaryotic transcript (5' UTR E1 I1 E2 I2 E3 I3 E4 UTR 3') will also be found in mRNA in the cytosol?

5' UTR E1 E2 E3 E4 UTR 3'

If a synthetic RNA containing repeating CGA bases is added to an in vitro translation system, what would the translated protein consist of?

Three classes of polypeptides consisting of arg repeats, asp repeats and thr repeats.

What sequence on the template strand of DNA corresponds to the first amino acid inserted into a protein?

5' CAT 3'

If the anti-codon contains the sequence 5’-AUG -3’ the DNA sequence that was the template for this RNA contains the sequence…

3'-TAC-5'

Although the two strands of DNA are complementary,

only one strand actually carries the genetic code for a particular gene.

Amino acids are attached through the ____end of the growing polypeptide chain to the _____group of the amino acid on the aminoacyl tRNA and therefore proteins are synthesized from the ______terminus to the _____terminus

carboxy ; amino; N; C

During translation of protein from RNA:

The amino terminus is produced first

Alternative splicing refers to

the inclusion or exclusion of different exons from the final processed mRNA

The reason for differences in RNA and proteins expressed in different cells of the same individual is that these cells contain different .

sets of regulatory proteins.

What are "sticky ends" with regard to DNA?

single-stranded DNA sequences that are generated by staggered cuts.

Which of the following is NOT a specific component of the lac operon of E. coli?

gene for RNA polymerase

Imagine a world in which proteins are made from 11 different amino acids. In this particular world, which of the following mutations in the coding region of a gene would not cause a frame-shift?

An insertion of 2 nucleotides

A molecule of tRNA with the anti-codon 5' CAG 3' will transport the amino acid

leucine (leu)

A primary transcript in the nucleus of a eukaryotic cell is often the functional mRNA, while a primary transcript in a prokaryotic cell is the functional mRNA.

larger than; the same size as

Steroid hormones produce their effects in cells by _.

Binding to intracellular receptors and promoting transcription of specific genes.

One way to detect alternative splicing of transcripts from a given gene is to _.

compare the sequences of different mRNAs made from the given gene

Transcription occurs along a template; forming an RNA in the _ direction

3' to 5'; 5' to 3'

Which of the following enzymes is required for CRISPR function?

nuclease

If two mutant strains are auxotrophic for compound X and one can grow when fed compound A or C, but not B, and the other can grow when fed C, but not A or B, which biosynthetic pathway is likely?

B-> A -> C -> X

Human DNA cut with restriction enzyme A can be joined to

bacterial DNA cut with restriction enzyme A.

Which of the following is unique to prokaryotic mRNA synthesis?

Coupled transcription-translation

Of the possible codons, specifiy amino acids and ___signal stop.

64; 61; 3

In the process of cloning eukaryotic DNA into prokaryotic cells, the role of reverse transcriptase is to make

double-stranded eukaryotic cDNA from mature mRNA

What is a genomic library?

a collection of the total genomic DNA from a single organism, stored in a vector

The single-stranded ends of DNA molecules can be joined together by

DNA ligase

A mutant yeast cell has a defective amino acyl synthetase that attaches proline to tRNA with the anticodon CCC. The consequence of this for the cell will be that

proteins will contain proline instead of glycine at positions specified by the codon GGG

What molecules are represented in a cDNA library?

mRNA

Most errors during DNA replication are repaired by__

3' to 5' proofreading exonuclease of DNA polymerase

DNA methylation and histone acetylation are examples of _.

epigenetic modifiers

A cell that has a lot of ribosomes attached to the endoplasmic reticulum is probably

synthesizing a lot of secretory proteins

Genomics is defined as the _.

study of an organism's complete set of DNA

The basic subunit of chromatin in a living cell is

nucleosome

Genes from one species can often be expressed in a different species. This is possible because of which property of the genetic code?

universiality

Not long ago, it was believed that a count of the number of protein-coding genes would provide an accurate estimate of the number of proteins produced in any given eukaryotic species. This is incorrect, largely due to the discovery of ____.

alternative splicing

For DNA probes to hybridize to a target

DNA strands must be complementary and anti-parallel to one another

If you start with one double-stranded DNA molecule and you perform SIX cycles of PCR, how many double-stranded copies of the DNA will you have?

64

E. coli is grown in the absence of glucose. Which of the following will be true?

The level of cyclic AMP will be high.

There is a mutation in the lacI repressor that results in a molecule known as a super-repressor because it represses the lac operon permanently. Which of these would characterize such a mutant?

It cannot bind to the inducer.

Which of the following is probably NOT a recognition site of a restriction enzymes

GCTTGC
CGAACG

CRISPR has been re-purposed as a method for gene editing. However, its real biological function is…

a mechanism for bacteria to defend themselves from viruses

UV light causes

covalent bonds between adjacent T bases

Which of the following is in the correct order for one cycle of polymerase chain reaction (PCR)?

Denature DNA; anneal primers; extend primers.

In nucleic acid hybridization,

DNA combines with complementary DNA

PCR requires all of the following EXCEPT

ligase