BIO 160 Chapter 10 Flashcards

1
Q

Chemical compositions DNA vs RNA

A

DNA RNA
Stands for: DeoxyriboNucleicAcid RiboNucleicAcid
Definition: A nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms. RNA, single-stranded chain of alternating phosphate and ribose units with the bases adenine, guanine, cytosine, and uracil bonded to the ribose. RNA molecules are involved in protein synthesis and sometimes in the transmission of genetic information.
Job/Role: Medium of long-term storage and transmission of genetic information The main job of RNA is to transfer the genetic code need for the creation of proteins from the nucleus to the ribosome. this process prevents the DNA from having to leave the nucleus, so it stays safe. Without RNA, proteins could never be made.
Unique Features: The helix geometry of DNA is of B-Form. DNA is completely protected by the body i.e. the body destroys enzymes that cleave DNA. DNA can be damaged by exposure to Ultra-violet rays The helix geometry of RNA is of A-Form. RNA strands are continually made, broken down and reused. RNA is more resistant to damage by Ultra-violet rays.
Predominant Structure: Typically a double- stranded molecule with a long chain of nucleotides A single-stranded molecule in most of its biological roles and has a shorter chain of nucleotides
Bases & Sugars: DNA is a long polymer with a deoxyribose and phosphate backbone and four different bases: adenine, guanine, cytosine and thymine RNA is a polymer with a ribose and phosphate backbone and four different bases: adenine, guanine, cytosine, and uracil
Pairing of Bases: A-T(Adenine-Thymine), G-C(Guanine-Cytosine) A-U(Adenine-Uracil), G-C(Guanine-Cytosine)
Stability: Deoxyribose sugar in DNA is less reactive because of C-H bonds. Stable in alkaline conditions. DNA has smaller grooves where the damaging enzyme can attach which makes it harder for the enzyme to attack DNA. Ribose sugar is more reactive because of C-OH (hydroxyl) bonds. Not stable in alkaline conditions. RNA on the other hand has larger grooves which makes it easier to be attacked by enzymes.

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2
Q

Describe the key features of the overall shape of a DNA molecule

A

double helix, sugar phosphate backbone.. base pairs inside..

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3
Q

Explain how the structure of DNA was determined

A

Crick was studying protein structure using x-ray crystallography. saw a x-ray image, saw basic shape was a helix the thickness of helix suggested two polynucleotides.. put backbones on the outside

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4
Q

What is the polarity of DNA?

A

negative

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5
Q

molecular bology

A

study of heredity at the molecular level

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6
Q

nucleotides

A

long chains of chemical units

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7
Q

full name of DNA

A

deoxyribonucleic acid

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8
Q

deoxyribose

A

sugar missing an oxygen

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9
Q

single ring structures

A

Cytosine and Thymine

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10
Q

double ring structures

A

Adenine and Guanine

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11
Q

Uracil

A

replaces Thymine in RNA

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12
Q

ribose

A

sugar in RNA

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13
Q

polynucleotide strands

A

double helix

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14
Q

DNA polymerases

A

enzymes that make the covalent bonds between the nucleotides of a new DNA strand

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15
Q

molecular chain of command

A

DNA=>RNA=> protein synthesis

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16
Q

transcription

A

transfer of genetic information from DNA to RNA

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17
Q

translation

A

translation from RNA to protein

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18
Q

why is one gene one enzyme not correct?

A

keratin is a product of a gene, many proteins have two or more different polypeptide chains.. each plypeptide is specified by its own gene

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19
Q

codons

A

three-base words

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20
Q

genetic code

A

the set of rule that convert a nucleotide sequence in RNA to an amino acid sequence

21
Q

AUG

A

start of a polypeptide chain and Methionine

22
Q

stop codons

A

UAA UGA UAG

23
Q

promoter

A

start transcribing signal

24
Q

RNA Elongation

A

2nd phase of transcription, RNA grows longer

25
Q

terminatior

A

end of the gene, 3rd phase of transcription

26
Q

mRNA

A

messenger RNA, the molecule that is translated into protein

27
Q

cap and tail

A

protect the RNA from attace by cellular enzymes and help ribosomes recognize the RNA as mRNA

28
Q

introns

A

noncoding regions

29
Q

exons

A

the coding regions - theparts of a gene that are expressed

30
Q

RNA splicing

A

introns are removed and exons are joined

31
Q

Translation players

A

mRNA, tRNA and Ribosomes

32
Q

tRNA

A

transfer RNA, the molecular interpreter.. pick up appropriate amino acids, and recognize the appropriate codons

33
Q

anticodon

A

on tRNA like the codon triplet on mRNA

34
Q

ribosomes

A

organelles that coordinate the functioning fo fthe mRNA and tRNA and actually make polypeptides

35
Q

Translation Process

A

initiation, Elongation, Termination

36
Q

Initiation

A

mRNA molecuel binds to a small ribosomal subunit.. tRNA binds to the start codon the initiator tRNA carries the amino acid methionine, anticodon A large ribosomal subunit binds to the small one, creating a functional ribosome

37
Q

Elongation

A

amino acids are added one by one to the first amino acid,
1. Codon Recognition
2. Peptide bond formation
3 Translocation

38
Q

mutation

A

any change in the nucleotide sequence of DNA

39
Q

virus

A

genes in a box

40
Q

bacteriophages

A

viruses that attack bacteria, bacteria eaters

41
Q

lytic cycle

A

after many copies of the phages are produced within the bacterial cell, the bacteria breaks open

42
Q

lysogenic cycle

A

viral DNA replication occurs without phage production or the death of the cell, many cell divisions.. prophage

43
Q

HIV

A

RNA virus with special twists

44
Q

retrovirus

A

RNA virus that reproduces by means of a DNA molecule

45
Q

reverse transcriptase

A

catalyzes reverse transcripton:Synthesis of DNA on an RNA template

46
Q

provirus

A

Viral DNA inserted into Chromosomal DNA

47
Q

viroids

A

small circular RNA molecules that infect plants

48
Q

prions

A

infectious protiens that cause brain diseases in animals