genome structure

Question 1

the dna in genes turns into rna through — in the — and the rna becomes poplypetide product through —- in —- and this polypeptide leads to structure and biological activity of the cell

Answer 1

• transcription
• nucleas
• translation
• cytoplasm

Question 2

—- is the length of the cell
—- is the full complement of dna an organism and has 25,000 genes

Answer 2

• gene
• genome

Question 3

the building blocks are —-
the c atoms in the sugar are numbered from —–
the dexoribose - the hydroxyl OH at carbon 2 is replaced by —-

Answer 3

• nucleotide
• 1’-5’
• H

Question 4

—- are the genetic code
pruine bases have — interlock rings
pyridine has —-

Answer 4

• bases
• 2
• one ring

Question 5

nucleotide triphosphate components are:

Answer 5

• base + 3 phosphate + sugar

Question 6

nucleotidetriphosphate join together to make —- , the covelent bond is in —– direction

Answer 6

• long strand aka polymer
• 3’ to 5’ phosphodiser
  ( c5 and c3 are not linked to a neighbouring sugar )

Question 7

dna structure:
- double helix w/ —– orientation
- —— backbone on the exterior
- —— on the interior
- ——–

Answer 7

-anti-parrel ( bc 5 and 3 go in the opposite direction )
- sugar phosphate
- purine and pyridine
- complementary base paring :
A-T ( 2 h bonds )
C-G ( 3 h bonds )

Question 8

—- means the dna strands are complementary

Answer 8

base pairing ( so basically the reflect example:
strand : 5’ AAT 3’
complementary strand: 3’ TTA 5’

Question 9

the sequence of the bases is the — form of genetic info

Answer 9

storage

Question 10

forces that hold the dna together are:

Answer 10

1- covelant bonds from 3’-5’ phosphodiser bonds along the dna backbone
2- non-covelent bond :
- base stacking: van der Waals interactions between the stacked base pairs is the strongest non covalent force in the structure

3- hydrogen bonds between the nucleotides:
g-c 3 h bonds ( are rich regions and more stable thermodynamically ) , a-t 2 h bonds ( rich regions that open for replication and transcription )

Question 11

—- looks like a string of beads , by which the dna wraps around 8 histones to make it

Answer 11

nucleosome strcuture

Question 12

8x histones ( H2A,H2B , H3 , H4)X2 are — charged and have — core particles while dna is — charged and have —- interactions
the H1 sites sits on —- od the core particles

Answer 12

• positivly
• octamer
• -ve
• ionic
• outside

Question 13

dna is highly organised and it wound around the nucleosome to make —- which is a highly copact organisation

Answer 13

• chromatin

Question 14

to make the chromosome this following steps must occur:

Answer 14

basic helix 1;1 —> nucleosome 1;6 —-> chromatin 1:36 —-> scaffold 1:6 —> loops of chromatin —> chromosome

Question 15

histones have — that aren’t involved in nuclease structure but are important for chromatin structure

Answer 15

tails

Question 16

—– tails are rich in — charged — residue and the modification of this — changes the chromatin structure

Answer 16

H3 + H4 , +ve , lysines , lysins

Question 17

histone modification facilitates —-

Answer 17

transcription

Question 18

the role of chromatin structure in regulating transcription is accessibility to —–

Answer 18

promotors and game sequence

Question 19

lysines are — charged and dna is — which will interact together o nigh neighbouring nucleosome and —- together , if they are acetylated then the positive charge becomes —-

Answer 19

• positive
• negative
• condense
• neutral

Question 20

—– promotes looser dna structure and aids transcription

Answer 20

acetylation
( enviornmental cues activates HATs and unwind dna , gene expressed then when no longer needed repressor activate HDACs)

Question 21

ppl have — individual molecules of chromosomes
giemsa stain is a — banded karyotyping during — is most condensed
—- the consisition aka no. of chromosome

Answer 21

• 46
• g banded
• metaphase
• karyotype

Question 22

elements of chromosomes:
—– essential for replicating - miotic spindle m characterised by repetitive dna and some specific to c/somes
—- points at which dna sythesis initiates and is essential for dna replication , multible For on human chromosome, speeds replication
—- caps the end of chromosome acts as a buffer and maintains the structural integrity

Answer 22

• centromer
• origin of replication
• tolemer
  ( check structure slide: 21)

Question 23

after — phase and before mitosis the chromosomes consist of —-

Answer 23

2 sister chromatid

Question 24

—- dark/light bands ( density of chromatin foldings)
—- highly condensed no transcription , dark , gene poor
—- extended , light , active transcprtion , gene rich

Answer 24

• banding ( trypsin / giemesta stain )
• hetrochormatin
• euchromatin

Question 25

true or false:
human genome consists of 30-35k genes and less than 5% of sequence is exonic

Answer 25

trueee

Question 26

what makes up the human gene? ( conserved about 5%)

Answer 26

1- promoter element ( proximal and core ) —> recruits proteins as RNAPOL2
2- 5’ untranslated region UTR —> era stability
3- exons —> amino acids coding sequence
4- introns —> splicing , poor undertsandig
5- 3 UTR —> mrna stability

Question 27

what makes up the non conserved part of the genome? ( non conserved refers to not under strong selection , can evolve relatively quick )

Answer 27

1- transpoons about 40% , mobile dna sequence that can migrate to diff regions of the genome
2- microstailities 5%
3- other repear dna about 50%