nature of gene and genome lecture 8

Question 1

who are watson and Crick?
why are they relevant?

Answer 1

watson and crick were 1st to propose structure of DNA and determine a mechanism of how DNA is copied

Question 2

shape of DNA

Answer 2

DNA has a spiral double helix structure

Question 3

components of DNA

Answer 3

Nitrogenous base
and repeating units of sugar and phosphate

Question 4

2 types of nitrogenous bases which ones are H bonded together

Answer 4

purines and pyrimidines

Question 5

where is DNA found in animal cells

Answer 5

nucleus

Question 6

Draw nucleus organelle

Answer 6

surrounded by nuclear envelope
has double membrane

Question 7

what does nucleus contain and state its role

Answer 7

produces ribosome
contains chromosomal DNA
site of DNA replication and transcription
communicates with cytosol via nuclear pore

Question 8

what is a genome,
where is it located
how many in a cell

Answer 8

each cell nucleus contains identical chromosomes in 2 copies.
each copy is a genome

Question 9

what is a gene

Answer 9

genes are functional regions of DNA
section of DNA that codes for functional RNA and proteins

Question 10

how many chromosomes are in human genome

Answer 10

22 pairs of autosome
1 pair of sex chromosome
23 homologous pairs= haploid
46 Homologous chromosomes= diploid

Question 11

what counts as human genome?

Answer 11

nucleus genes+ Mitochondria genes

Question 12

what counts as plant genome

Answer 12

chloroplast genome+ nucleus genes

Question 13

Mitochondrial gene -
how many genes does it contain?

Answer 13

mitochondria contains circular chromosome
mitochondria DNA contains 37 genes- non coding and coding regions(rRNA, tRNA)

Question 14

Draw+ label homologous chromosomes

Answer 14

-telomere
- centromere
- paternal homolog
- maternal homolog

Question 15

How is DNA packed into chromosome- stages

Answer 15

Double helix DNA
Nucleosome
chromatin
coiled-coil
chromosome

Question 16

what is nucleosome?

Answer 16

DNA histone complex
there are 4 core histones which bind to DNA in any combination-
-H2A
-H2B
-H3
-H4

Question 17

What does central dogma mean

Answer 17

theory that states genetic information flows in one direction only
DNA-RNA-Protein

Question 18

what is Transcription

Answer 18

synthesis of mRNA from DNA
same language: nucleic acid

Question 19

translation

Answer 19

protein synthesis from mRNA
different language- nucleic acid to protein

Question 20

types of nucleic acid

Answer 20

deoxyribonucleic acid and ribonucleic acid

Question 21

differences B/W DNA and RNA

Answer 21

in DNA sugar is deoxyribose in RNA is ribose
deoxyribose lacks 1 oxygen

Question 22

2 types of nitrogenous bases

Answer 22

-pyrimidine 1 ring cytosine thymine uracil
-purines 2cyclic rings (adenine and guanine)

Question 23

what makes a nucleoside

Answer 23

sugar+ base bonded with beta glycosidic linkage

Question 24

what makes a nucleotide and draw

Answer 24

sugar, base and phosphate
ribonucleotide monomers make RNA polymer
deoxyribonucleotide monomers make DNA polymer

Question 25

differences B/W deoxyribose and ribose sugar

Answer 25

deoxyribose sugar doesnt have oxygen on carbon 2

Question 26

how is DNA formed

Answer 26

DNA is a double stranded helix as determined by watson and crick
when 2 mononucleotides join together a molecule of water is eliminated(condensation)
2 polynucleotide strands run antiparalel to each other
5’ - 3’ 3’>5’
bases form h bonds with each other twisting the DNA to form a helical structure

Question 27

what if importance of nucleotides rather than being just building blocks?

Answer 27

ATP is energy source of cells
ATP is made of nucleotide derivative

Question 28

complementary base pairing in DNA

Answer 28

occurs B/W complementary bases by H bonding
amount of purine= amount of pyrimidine
ratio of A:T and C:G is one to one

Question 29

how are grooves made?
2 types of grooves

Answer 29

in the double helix model bases are stacked on top of each other base stacking angles produces 2 grooves
major groove larger angle
minor groove smaller angle

Question 30

different forms of DNA

Answer 30

1. A form- mostly when DNA is dehydrated or in crystaline formor in combination with RNA shorter, more compact, right handed helix
2. B-form: most common- right handed
3. z form- left handed helix forms as part of stress coiling or interaction with proteins

Question 31

triplet code, codon

Answer 31

each 3 bases form triplet code on DNA
1 codon= 1 AA Codon is on mRNA
Anticodon is on tRNA

Question 32

DNA vs RNA

Answer 32

• ribose/ deoxyribose
• RNA is single stranded helix
• ATCG / AUCG

Question 33

Types of RNA

Answer 33

• messanger RNA- transcript read from DNA
• transfer RNA- translation carries AA to ribosome
  anticodon on tRNA pairs with codon on mRNA
• ribosomal RNA - eukaryote RNA participate in protein synthesis

Question 34

tRNA structure and draw it

Answer 34

2D clover leaf structure
H bonds
single stranded folded into a clover shape
aa attachment site
anticodon

Question 35

what does non coding regions of RNA do

Answer 35

not all RNA codes for protein
remainin are non coding RNA
* rRNA and tRNA
* small nuclear RNA(snRNA) found in nucleus is part of splicing
* small nucleolar RNA(SnoRNA) involved IN methylation of rRNA
* small cytoplasmic RNA(scRNA) plays role in expression of some genes