GENETICS - EXAM THREE

DNA stores information in __________

base sequence (A, T, G, C)

A pairs with _____; G pairs with _____

T; C

complimentary (A-T, G-C) structure results in _____

DNA replication

double helix structure results in _____

antiparallel strands

DNA must:

1.) store information

2.) replicate accurately

DNA _____ drive self-replication

polymerases

chromatin

dynamic DNA-protein structure

histones

positively charged proteins

nucleosome

basic unit of DNA compaction (“beads on a string”)

telomeres

required for chromosome stability

telomerase

extend telomeres

hayflick limit

finite number of cell divisions

DNA synthesis occurs along the chromosomes at the __________.

replication bubbles

DNA replication occurs within the replication bubbles at the __________.

replication forks (2; bidirectional)

many proteins are required for DNA replication:

DNA helicase, single strand binding proteins, DNA primase, DNA polymerases, RNAse, DNA topoisomerase

DNA replication can be done __________ in a test tube.

in vitro

requirements for the polymerase chain reaction:

DNA template and an existing nucleic acid (-OH)

who invented polymerase chain reaction

Kary Mullis in 1984

what is polymerase chain reactions used for

gene cloning, DNA sequencing, diagnostic testing, parental testing

DNA polymerases synthesize __________

5’ → 3’

error rate is ______

600,000 errors/S-phase

_____ reduces the error rate to 3-6 errors/S-phase

proofreading

what does proofreading detect?

non-based-paired nucleotides

function of DNA helices

unwinds DNA

function of SSB proteins

stabilize single strands

function of DNA topoisomerase

relives supercoiling

function of DNA polymerase

synthesize DNA

steps of a polymerase chain reaction

1.) denaturation

2.) annealing

3.) elongation

cancer cells have a _____ telomerase activity and _____ telomeres.

high; stable

As telomeres shorten, the _____ come off and negatively regulate division.

TATA-box binding protein

composition of chromosomes: _____ + _____ = _____

DNA + histone proteins = chromatin

5 histone proteins that construct the nucleosome:

1.) H1 (1 copy)

2.) H2A (2 copies)

3.) H2B (2 copies)

4.) H3 (2 copies)

5.) H4 (2 copies)

DNA is extensively compacted into _____.

chromatin

1.) a nucleosome consists of _____ molecule looped twice around a core of _____.

2.) a loosened fiber shows a “bead-on-a-string” organization. the “string” is the _____, each “bead” is the _____.

3.) when the coiled coils unwind, _____ and _____ are organized as a _____.

4.) when a chromosome is at its most condensed, the _____ is packed into _____.

1.) DNA; histone proteins

2.) DNA; nucleosome

3.) DNA and proteins; cylindrical fiber

4.) DNA; tightly coiled coils

the shape and function of a protein are dictated by the __________.

sequence of amino acids

the sequence of amino acids is dictated by the __________.

sequence of nucleotides (DNA) of a gene

each codon instructs which _____ is to be deposited during __________.

amino acid; protein synthesis

pathway for cell to function

1.) locations specific gene

2.) transcription

3.) transports copy to site of protein synthesis (ribosome)

4.) translate

5.) destruction of copy

the protein coding information stored in DNA is accessed and used in 2 steps:

1.) transcription

2.) translation

what is the central dogma?

flow of genetic information

steps of central dogma

1.) DNA replicates

2.) transcription

3.) RNA replicates

4.) translation

5.) protein

transcription is located in the _____ and its output is _____.

nucleus; RNA

translation is located in the _____ and its output is _____.

cytoplasm; protein

there are an estimated _____ protein coding genes

25,000

there are an estimated _____ non-coding RNA encoding genes

20-25,000

3 types of RNA encoding genes

rRNA, miRNA, IncRNA

transcription start site

+1

2 transcription factors

bind to TATA box and increase in RNA polymerase

upstream in transcription

negative numbers

downstream in transcription

positive numbers

promoter-specific transcription factors

regulate specific genes

transcription initiation complex

assembly of RNA polymerase and transcription factors that bind to a promoter

different cells express __________.

different genes

estrogen receptor

hormone-regulated transcription factor

p53

activates gene expression in response to DNA damage; results in division or apoptosis

tamoxifen

a drug that blocks the estrogen receptor and is an anti-cancer treatment

TATA box

-35

exons carry the _____ for __________.

codon; protein synthesis

5’ CAP is added by ____

guanyltransferase

5’ CAP protects _____ and aids in _____

RNA; translation

poly-A tail is added by _____

poly A polymerase

the poly A tail is required for _____ and getting out of the _____ to reach the _____.

stability; nucleus; ribosome

splicing is performed by _____

spliceosome (proteins + snRNA)

RNA sequences base pair with _____ to identify __________.

snRNAs; exon-intron borders

spliceosome has _____ proteins and _____ snRNAs.

80-100; 6

exons are _____ in RNA splicing.

kept

introns are _____ in RNA splicing.

removed

alternative splicing

increase in protein coding capacity and protein diversity

each exon contains the _____ for the part of the protein.

codon

different codons result in __________ being made from the same gene.

different proteins

splicing defects

a mutation that would lead to the skipping of an exon

ex: cardiomyopathy, ALS

the human microbiome is all the ________ that live in our bodies and do not cause disease.

bacteria, archaea, fungi, and protozoa

microbial antagonism

process where natural members of our microbiome help protect us from pathogens

bioburden

the amount of bacteria that makes up the skin, mouth, intestinal tract, and genitourinary tract

______ of our normal biota can sometimes cause disease if proper conditions arise.

microbe

dysbiosis

unbalance of bacteria in the gut microbiome

prebiotics

consuming plant fibers that can only be digested by the microbiome

probiotics

ingesting living microbes

example of microbiome dysbosis

C. diff

a doctor may prescribe a ___________ to a pt with C. diff

fecal microbiota transplant

the human adult skin on average covers about _____ of surface area and has _____ microorganisms.

2 square meters; 1 trillion

nasopharynx

area from nose to oral cavity

oropharynx

area between soft palate and upper edge of epiglottis

the surface area exposed to air in the respiratory tract is about _____.

750 square feet

the importance defense mechanism of the stomach is its _____

acidity

a stomach’s acidity plays a role in __________.

preventing infections

bacteria can be find in the _________ of the stomach

mucous lining

H. pylori is a stomach infection that can cause _____.

gastric ulcers

the duodenum and jejunum are _____.

slightly alkaline

the ileum, cecum, and colon are _____.

slightly acidic

_____ may influence weight gain.

methanogens

_____ and _____ are sterile environments of the genitourinary tract.

kidneys and ureters

Women whose vaginal composition is not predominantly _____ species tend to be more prone to infections and STDs.

Lactobacillus

How are members of our own microbiota kept from slipping past our own cells and infecting us?

physical barries

the major barrier separating us from our microbiota is a layer of __________ that lines the mucosa of our digestive, genitourinary, and respiratory tracts.

glycoprotein-covered epithelial cells

the BBB has __________ between the endothelial cells of capillaries to the brain.

very tight junctions

3 parts of mRNA translation to protein

1.) mRNA

2.) tRNA

3.) ribosome

mRNA

copy of info in DNA (genes) and transported to ribosome

tRNA is _____ and has around _____ nucleotides.

small; 80

structure of mRNA

5’ UTR, open reading frame, 3’ UTR