nucleic acid, dna, rna Flashcards

1
Q

name and describe the 4 genetic processes in macromolecular synthesis

A
  1. replication- DNA synthesis from existing DNA
  2. transcription- RNA synthesis from DNA
  3. translation- protein synthesis from decoding RNA
  4. RNA modification- modify RNA in nucleus
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2
Q

describe the structure of a nucleotide

A

pentose sugar- deoxyribose, ribose
phosphate
nitrogenous base- adenine, thymine, uracil, guanine, cytosine
sugar phosphate backbone is formed from phosphodiester bonds, hydrogen bonding occurs between bases, always from 5’ to 3’

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3
Q

what are purines and pyrimidines

A

purines have 2 rings and pyrimidines have 1 ring
-purine: A G
-pyrimidine: U T C

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4
Q

structure of DNA

A

-double stranded
-ATCG
-asymmetrically aligned causing major and minor grooves which allow factors to interact with the bases
-46 chromosomes
-DNA packed into chromatin then into chromosomes
-DNA wraps around nucleosome
-centromere= constricted region of chromosome that’s involved in the segregation of chromosomes
-end of each chromosome has a telomere (noncoding region that protects structure)
-telomere shortens with each successive replication to prevent more replication
-nucleosome regulates gene expression by determining if DNA can be accessed by transcription factors
-modification of amino group of histone changes shape and electrical charge to prepare chromatin for DNA rep/transcip.

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5
Q

what are nucleosomes and what do they regulate

A

histones, regulate gene expression by determining if DNA can be accessed by transcription factors

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6
Q

what is a telomere and what happens to it when replication occurs

A

non coding region that protects the structure, shortens with each successive replication to prevent more replication

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7
Q

what is a centromere

A
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8
Q

what does enzymatic modification of amino terminal of histones do

A
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9
Q

describe the structure of RNA

A

-AUGC
-3’ to 5’
-phosphodiester bonds, single stranded
-forms secondary and tertiary structures by folding and pairing with itself

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10
Q

name the types of RNA

A

mRNA
tRNA
rRNA

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11
Q

what is mRNA

A

carries genetic information from DNA to cytoplasm for translation

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12
Q

what is tRNA

A

carries amino acids to ribosome to make proteins, cloverleaf shape

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13
Q

name other uses of nucleotides

A

-energy
-intracellular communication

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14
Q

differences between DNA and RNA

A

DNA- double stranded, ATCG, deoxyribose
RNA- single stranded, AUCG, ribose, can catalyse reactions, different types

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15
Q

DNA replication how

A
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16
Q

what are structural genes

A

proteins that encode for proteins

17
Q

what enzyme is used to transform DNA into RNA

A

DNA dependent RNA polymerase
pol i transcribes rRNA
pol ii transcribes tRNA

18
Q

describe a genes structure

A

5’–[]–//-[]-[]———-3’
-other regulatory sequences, promoters, coding regions
promoter sequence initiates transcription, factors bind and release RNA polymerase which needs to be phosphorylated to be activated

19
Q

what are promoter regions

A

specific sequence in DNA that determines where RNA polymerase binds

20
Q

how is RNA polymerase activated

A

phosphorylated

21
Q

DNA transcription summary

A

-RNA from DNA using RNA polymerase
-DNA copied in 3’ to 5’ so the RNA synthesised is 5’ to 3’
-RNA polymerase doesnt need primer to start (DNA poly needs it)
-initiation needs several protein factors to allow efficient RNA polymerase binding to promoter

22
Q

describe eukaryotic genes

A

-theyre modified to remove introns
(splicing) before mRNA is made
-contains exons and introns
exons= coding regions of protein
introns= non-coding regions

23
Q
A