gene expression and epigenetics

Question 1

it is the collection of mRNAs in a cell

Answer 1

transcriptome
- complete cell of RNA molecules (transcripts)
*mRNA
* non coding RNA (rRNA, tRNA)

[In simple terms, the transcriptome is like a snapshot of all the “messages” (RNA) a cell is sending out at a particular time, showing which genes are active and what the cell is doing or planning to do.]

Question 2

it occurs over time at the molecular and organ levels

Answer 2

changes in gene expression

Question 3

single-cell transcriptomics catalogs -
proteomics catalogs -

Answer 3

single-cell transcriptomics catalogs - mRNAs in a cell
proteomics catalogs - proteins in a cell

Question 4

briefly explain the globin chain switching

Answer 4

hemoglobin is made up of 2 globular protein chains:

1. beta chain globin grp
2. alpha chain globin grp

*each globin surrounds an iron containing chemical group called heme group

embryonic > fetal > adult
as human develops, different globin polypeptide chains specifically in the hemoglobin r used in the process

Question 5

what are the implications does the presence of the multiple conformations in hemoglobin have for cellular function is in relation

Answer 5

these different shapes allow hemoglobin to pick up oxygen in the lungs and release it where it’s needed

Question 6

in all tissues and organs, genes are turned on and off during development. hence, what does the stem cells do

Answer 6

self-renew and yield more specialized daughter cells

Question 7

exocrine progenitor cell vs endocrine progenitor cell

Answer 7

exocrine progenitor cell:
release digestive enzymes into ducts

endocrine progenitor cell
secrets hormones directly int the blood streams

*endocrine cells clusters are called the islets of Langerhans

Question 8

it is activated and controls expression of other genes in a way that stimulates some progenitor cells to divide.

Answer 8

transcription factor

Question 9

to connect disease that shone genes with altered expression

Answer 9

diseasome
- determine how proteins will be related with related functions and which can be rebuilds links between medical conditions

[map shows how different diseases may be related at the genetic level, even if they seem very different]

Question 10

it can control the functioning of larger proteins

Answer 10

microproteins
- can interact with larger proteins and affect how they work, either enhancing or blocking their functions.

Question 11

microRNAs

Answer 11

bind to certain mRNAs
preventing their translation into proteins

Question 12

chromatin remodeling

Answer 12

dna is wrapped arnd histones
these histones can be rearranged to either expose certain parts of dna to transcription factors or keep other parts hidden
exposed parts can be turned on to make proteins, while hidden parts are off

Question 13

it adds or removes certain small chemical groups to or form histones

Answer 13

chromatin remodeling

Question 14

what are the 3 major types of small molecules that bind to histones

Answer 14

adds:
acetyls , CH3CO2
- histones play in controlling in expression lies in the acetyl grp
phosphates, PO4-

removes:
methyl, CH3

overall = more fair favorable chromatin structure for transcription, thereby promoting gene expression

Question 15

what happens when one acetyl groups are added to particular aa in the tails of certain histones

Answer 15

the tata box becomes accessible to transcription factor

Question 16

these help the small and large protein complexes ease movement of the tata box away from the histones, enabling transcription to proceed

Answer 16

H3and H4

Question 17

how many base pairs are wrapped around a nucleosome

Answer 17

only 146 base pairs

Question 18

These changes in gene expression are heritable from cell generation to cell generation, but they do not alter the DNA base sequence

Answer 18

epigenetic
*addition and removal of acetyl, mehyl or phosphate grps

Question 19

what happens when the chromatin opens to allow transcription factors to bind

Answer 19

microRNAs bind to specific mRNAs
blocking their translation into protein

Question 20

it is a type of noncoding RNA

Answer 20

MicroRNA
- 21 to 22 bases long
- they do not encode an amino acid sequence

Question 21

closed chromatin vs open chromatin

Answer 21

closed chromatin
- heterochromatin
- tightly packed

open chromatin
- euchromatin
- ez to read
- loosely packed

Question 22

__ genes > __ mRNAs > __ proteins

Answer 22

20 325
100 000
1 million

Question 23

it can fit inside the nooks and crannies of large proteins, such as cell surface receptors and ion channels, affecting their functioning.

Answer 23

microproteins

Question 24

which is smaller? microproteins or transcription factors

Answer 24

Transcription factors are small, but not nearly as tiny as the microproteins, which are fewer than 100 amino acids long

Question 25

splicing is also known as

Answer 25

post-transcriptional modification

Question 26

what are the enzymes used to remove the introns

Answer 26

spliceosomes

Question 27

this create different forms (isoforms) of protein from the same gene

Answer 27

alternative splicing

Question 28

A virus mass produces itself using the infected cell’s transcriptional and translational machinery.

Answer 28

viral dna

Question 28

how many percent of human DNA encode protein

Answer 28

1.5%
- most of the human genome does not encode protein
- non protein encoding part of the genome:
viral sequences
sequences that encode noncoding RNAs
pseudogenes
introns
promoters
other controls
transposons

Question 29

what enzyme does the retroviruses copy its genetic material into dna, which inserts into a host chromosomes

Answer 29

reverse transcriptase

Question 30

Some noncoding RNAs correspond to DNA sequences

Answer 30

pseudogenes
- similar in sequence to a protein-encoding gene that may be transcribed, but it is not translated into protein.

Question 31

function of
viral dna:
NONCODING RNA GENES
tRNA genes:
rRNA genes:
long noncoding RNAs:
pseudo genes:

Answer 31

viral dna:
evidence of past infection

NONCODING RNA GENES
tRNA genes:
connect mRNA codons to aa

rRNA genes:
parts of ribosomes

long noncoding RNAs:
control of gene expression

pseudo genes:
dna sequence v similar to known genes that r not translated

Question 32

The most abundant type of repeat is a sequence of DNA that can move about the genome

Answer 32

transposon or “transposable element”