biochem exam 3 genes and chromosomes

Question 1

Information pathway

Answer 1

in which the genetic information is stored as nucleotide sequence and is maintained and expressed

Question 2

gene

Answer 2

is a chromosomal segment that encodes for a single polypeptide chain, RNA molecule serve as a regulatory function

Question 3

genome

Answer 3

contains the total genetic information of a cell, organism or a virus

Question 4

chromosome

Answer 4

is a compact strand of DNA that is encoded with genes it has chromatin formed during nuclear division

Question 5

chromatin

Answer 5

DNA complex with histones and other proteins and is typically dispersed throughout the nucleus during interphase

Question 6

transcription

Answer 6

one strand of the double stranded DNA is serve as a template for the mRNA for transcription

Question 7

translation

Answer 7

the triplets of nucleotides in the mRNA bind to the complementary triplets in the tRNA
-The tRNA it carries the specific Amino acids needed for protein synthesis

Question 8

three nucleotides

Answer 8

codon

Question 9

nucleoid

Answer 9

in bacteria the negative supercoiling of the DNA compaction
-the nucleoid exist in the cytosol

Question 10

Craig venter

Answer 10

suggest that the living organism could get less than 400 genes

Question 11

viral genomic DNA

Answer 11

associated with capsid

Question 12

prokaryotic DNA

Answer 12

associated with nucleoid

Question 13

eukaryote DNA

Answer 13

is organize proteins into a complex called chromatin

Question 14

mature transcript

Answer 14

introns are removed after transcription
exons are joined together

Question 15

transposons

Answer 15

sequence called transposons the can move around within the genome of a single cell
-account for 50% of the human gemone

Question 16

SSRs

Answer 16

Simple Sequence Repeat
-Also called satellite because when fragment and centrifuged the DNA separates into discrete satellite\
-It has capsomeres and telomeres

Question 17

centromere

Answer 17

is a region that hold the two daughter chromosomes together
-contains each equally divided set of chromosome sets to daughter cell

Question 18

Telomere

Answer 18

it caps the ends of each chromosome
-prevent DNA from unraveling
-Is added by enzyme telomerase

Question 19

Hayflick limit

Answer 19

52
is the number of the human genome can divide before loosing ability to divide
-in each replication the telomere shortens

Question 20

normal B form

Answer 20

relaxed DNA

Question 21

linear DNA

Answer 21

is underwound and has proteins to prevent the DNA from rotating

Question 22

linking number

Answer 22

describes supercoiling
how many base pairs normal vs how many base pairs per turn

Question 23

topoisomers

Answer 23

is DNA that only differs in the linking number
has the same number of base pairs but only differ on the degree of supercoiling

Question 24

topoisomerases

Answer 24

enzymes that are required for DNA unwinding and rewinding and are required during DNA transcription and replication

Question 25

Type I Topoisomerase I and III topoisomerases

Answer 25

make a transient cut in one strand of the DNA and changes the lk increase by 1

Question 26

Type II topoisomerases

Answer 26

make a transient cut in both DNA strand and changes the lk by 2
-Is called DNA gyrase
-Decreases the LK
-Uses ATP and double stranded breaks

Question 27

Coumarins (novobiocin and coumermacycin

Answer 27

inhibit topo II from binding to ATP

Question 28

nucleosomes

Answer 28

DNA and protein are packed into discrete units

Question 29

histones

Answer 29

DNA associated tightly with proteins called histones
-the amino terminal stick out
-54 bp
-binding site of histones is A-T rich regions

Question 30

SMC

Answer 30

structural maitenance of chromosomes

Question 31

cohesins

Answer 31

link sister chromatids

Question 32

condensin

Answer 32

help chromosomes to condense create positive super coil