Biology Module 7

Question 1

Nucleotide

Answer 1

Building blocks of nucleic acids, include sugar (ribose for Rna, deoxyribose for Dna) a nitrogenous base, and phosphate group

Question 2

DNA double helix

Answer 2

Twisted ladder with twin tails of sugar-phosphate backbones alternating units of deoxyribose + phosphate joined by covalent bonds, two chains are antiparallel

Question 3

3 prime (3’) or 5 prime

Answer 3

End of nucleic acid terminating at third of fifth carbon of sugar molecule

Question 4

Base pairs

Answer 4

Adenine (A) Thymine (T) and Guanine (G) Cytosine (C) joined by hydrogen bonds

Question 5

Purines

Answer 5

Bases with double ring structure (A + G)

Question 6

Pyrimidines

Answer 6

Bases with single ring (C + T)

Question 7

Complementary

Answer 7

A pairs with T or U, G pairs with C

Question 8

Genome

Answer 8

All the genetic info in organism, one circular DNA in bacterial cell, divided among linear chromosomes in Eukaryotic

Question 9

Gene

Answer 9

Sequence of DNA that encode a specific protein or RNA molecule

Question 10

Central dogma

Answer 10

Relationship between nucleic acids and proteins as a flow of information

Question 11

Transcription

Answer 11

Cell produces RNA using DNA as template

Question 12

Translation

Answer 12

Info in RNA is used to assemble protein

Question 13

RNA

Answer 13

Intermediate between DNA and protein nucleotides contain sugar ribose as nitrogenous base iris cell, which binds with adenine in complementary base pairs, can be single stranded and catalyze chemical reactions

Question 14

Messenger RNA

Answer 14

Carrie’s info that specifies a protein divided into genetic codeword codons group of three consecutive MRNA bases that correspond to one amino acid

Question 15

Ribosomal RNA

Answer 15

Combines of protein to form a ribosome the physical location were translation occurs some help correctly align ribosome others catalyze formation of the bonds between amino acids in developing protein

Question 16

Transfer RNA

Answer 16

Molecules are connectors that bind an mRNA codon at one end in a specific amino acid, other role is to carry amino acids to ribosome to correct spot along mRNA molecule

Question 17

Template strand

Answer 17

Contains the DNA sequence that is transcribed to RNA usually two strands

Question 18

Promoter

Answer 18

DNA sequence that signals a gene start in indicates which strand is the template

Question 19

Stages of transcription

Answer 19

Initiation: RNA polymerase attaches to promoter and unzipped DNA double helix exposing template strand
Elongation: RNA polymerase moves along DNA template strand in 3-5’ direction adding RNA nucleotides complementary to exposed bases on 3’ end
Termination: DNA signals end of gene upon reaching terminator RNA Pommer enzyme separates from DNA template releases, newly produce RNA, DNA molecule resumes double helix shape

Question 20

Gene expression

Answer 20

Production of either functional RNA molecule or protein

Question 21

5’ cap

Answer 21

After transcription, short sequence of modified nucleotides are added to 5’ end of mRNA molecule

Question 22

Poly A tail

Answer 22

Formed by 100-200 adenine added to 3’ end

Question 23

Cap + Tail

Answer 23

Enhanced translation by protecting mRNA, from being degraded in cytoplasm and help ribosomes attached to 5’ end of mRNA molecule

Question 24

Intron

Answer 24

Portions of mRNA that are removed before translation, small, catalytic RNA and proteins remove intron from mRNA.

Question 25

Exons

Answer 25

Remaining portions that are spliced together to form, mature, mRNA that leaves nucleus to be translated, mRNA have 70+

Question 26

Genetic code

Answer 26

Set of rules by which a cell uses the codons in mRNA to assemble amino acids into a protein

Question 27

Codon

Answer 27

A group of free RNA bases corresponding, either to one amino acid, or to a stop signal

Question 28

First codon

Answer 28

AUG

Question 29

Stop codons

Answer 29

UGA, UAA, UAG

Question 30

Anticodon

Answer 30

Found in tRNA freebase loop that is complementary to one mRNA codon

Question 31

Stages of translation

Answer 31

Initiation: small, ribosomal, subunits bind to 5’ end of mRNA include region of untranslated nucleotides between cap and start codon, which attracts tRNA, carrying amino acid methionine Elongation: tRNA carries second amino acid to second codon where they bind amino acids align and covalent bond is formed peptide bond, release of tRNA ribosomes move down, mRNA by one codon Termination: ribosome reaches, stop, codon, release factor binds to stop codon release last TRA ribosome units, separate and recycle new polypeptide release proteins that must fold correctly

Question 32

Operon

Answer 32

Group of related genes, plus a promoter and operator that control the transcription of the entire group at once

Question 33

Promoter (transcription)

Answer 33

Site which RNA polymerase attaches to begin transcription

Question 34

Operator

Answer 34

DNA sequence located between promoter and protein and encoding region

Question 35

Repressor

Answer 35

Protein that when bound to operator prevents transcription of genes

Question 36

Lac operon

Answer 36

Consist of three genes that code lactose degrading enzyme, promoter and operator

Question 37

Regulatory tags

Answer 37

Enzymes in cell can modify stretches of DNA by adding or removing the sec consisting of methyl groups

Question 38

Epigenetics

Answer 38

Study of changes in gene expression that don’t involve changes in DNA sequence

Question 39

Transcription factors

Answer 39

Proteins that bind DNA at specific sequences that regulate transcription may bind to gene promoter or enhancers

Question 40

Enhancer

Answer 40

Regulatory DNA sequence that lies outside the promoter may be located near gene or within, but thousands of base pairs away

Question 41

Signal transduction

Answer 41

Hormone or others binds to outside of cell and trigger series of chemical reactions inside cell mRNA, must exit nucleus and attach to ribosome for protein production

Question 42

microRNA

Answer 42

Complementary to coding mRNA, when combined silence genes

Question 43

Mutation

Answer 43

Any change in a cells DNA sequence

Question 44

Substitution mutation

Answer 44

Replacement of one DNA base with another

Question 45

Missense mutation

Answer 45

Sub mutation changes a base triplet, so it specifies to different amino acid

Question 46

Nonsense mutations

Answer 46

Based triplets specifying, amino acid changes into one that encode stop codon, which shorten protein product

Question 47

Insertion mutation

Answer 47

Adds 1+ nucleotides to a gene

Question 48

Deletion mutation

Answer 48

Removes nucleotides

Question 49

Frameshift mutation

Answer 49

Nucleotides are added, or deleted by a number other than multiple of three which disrupts codon reading frame and devastates proteins function

Question 50

Expanding, repeat, mutation

Answer 50

Number of copies of a free or four nucleotide sequence increases over several generations

Question 51

Mutagens

Answer 51

Any external agent that includes mutations, such as radiation or pollution?

Question 52

Transposable element/transposon

Answer 52

DNA sequence that can jump within the genome, if landed ingene can disrupt it

Question 53

Germ line mutation

Answer 53

DNA sequence changed that occurs in cells that give rise to sperm and eggs, are heritable

Question 54

Somatic mutation

Answer 54

Occurs in nonsex cells, not heritable

Question 55

Alleles

Answer 55

Variants of genes, ~25,000 in humans

Question 56

Homeotic genes

Answer 56

Encode transcription factors that are expressed during the development of an embryo, control formation of organisms body parts

Question 57

DNA -> transcription-> RNA -> translation

Answer 57

Protein

Question 58

DNA to RNA letters

Answer 58

AGTC UCAG

Question 59

DNA polymerase

Answer 59

responsible for the process of DNA replication, during which a double-stranded DNA molecule is copied into two identical DNA molecules.