dna, rna and protein synthesis test 1 Flashcards
what does dna stand for
deoxyribo nucleic acid
what is dna organised into
chromosomes
where is dna stored
the nucleus
what structure does dna have
double helix
what is dna made of
nucleotides
what are the elements of a DNA nucleotide
phosphate, deoxyribo sugar and nitrogen base
which parts of nucleotide parts of the nucleotide make up the backbone of the dna
the phosphate and the deoxyribo sugar
what are the complementary strands
dna strands whose bases match, complement each other
what are the types of bases for dna
adenine, thymine, guanine, cytosine
what are the base pairing rules for dna .
A goes with T, G goes with C
why are dna strands considered anti parrallel
because the strands run in opposite directions
which directions do dna strands run
3 prime to 5 prime , and 5 prime to 3 prime
what are the bonds between DNA nitrogen bases
hydrogen bonds
why are bonds between nitrogen bases so weak
so the bonds can be easily broken and bases can detach for RNA synthesis or DNA replication
what does RNA stand for
ribonucleic acid
how are rna sugar and dna sugar diffrent
rna is ribose , dna is deoxyribose sugar
what is the structre for rna
single stranded
what are the nitrogen bases for rna
adenine, uracil, guanine, cytosine
what is the monomer for rna
nucleotides
who discovered the structure of dna
james watson, francis crick
why can rna leave the nucleus but not dna
rna is small enough to fit through the nucleus pores but dna is not
what is dna replication
process in which dna makes a copy of itself
what part of mitosis does dna replication occur
interphase
why is dna replication considered semi conservative
because half of the old strand is saved for every new strand
what are the main steps for dna replication .
- helicase unzips dna molecule, separating the strands
- dna polymerase use half of old strand as a template for a new strand
- ligase seals any gaps in the dna to make one cohesive molecule
what is the result of 1 na molecule replicating
2 new semi conservative dna molecules
what does primase do in dna replication
lays down primer
what type of protein is vital to dna replication
enzymes
how does the ‘‘new’’ side of replicated dna form
nucleotides floating around attach on
what is a gene
a section on dna that codes for one protein
what does one protein code for
one trait
how do proteins run living organisms
they make up the enzymes and structures
what does mRNA do
it’s a copy of a gene that carries the code from the nucleus to the rest of the cell
what does rRNA do
along with certain proteins , its makes of the ribosomes that make proteins
what does tRNA do
during protein synthesis, tRNA transfers amino acids to the ribosomes
what is transcription
making mRNA copies from DNA
what are the steps for transcription
- double stranded dna unzips
- dna is used as template , dna bases are matched with complementary rna bases
when matching DNA bases for RNA, what does A match with
Uracil
what enzyme is used for mRNA synthesis
rna polymerase
where does mRNA go after leaving the nucleus
it goes to the ribosomes in the cytoplasm
what is translation
proteins being built from instructions of RNA
how does mRNA code for amino acids
in triplets- 3 letters code for one amino acid
what are the steps in translation .
- mRNA goes to ribosome
- mRNA attaches to a completementary strand of tRNA with amino acid
what is the ribosome’s role in translation
it links the amino acids and separates them from the tRNA
what is a codon
three mRNA letters that code for one amino acid
what is an anti- codon
three tRNA letters with 1 amino acid attached that connects to 3 complementary mRNA letters
why are there several codons for each amino acid
mutation insurance
what does a start codon indicate
beggining of a protein
what does stop codon indicate
the end of a protein
whats the start codon
AUG, methionine
whats an allele
a diffrent version of a gene
whats a mutation
changes in DNa that affect genetic information
what are the steps of the possible outcomes of a mutation
chnages dna
changes rna
may change protein
may change trait
what 3 things can cause mutation
mistake when dna is copied
inherited mutations
enviromental factors
when can inherited mutations occur
when there are mutations in the sperm or egg (gametes )
what’s another way to say envirmoental factors
mutagens
some examples of mutagens
cigarrette smoke, x rays, uv rays, pesticides
how often do mutations happen
regularly
almost all mutations are what
neutral
what does it mean for a mutation to be neutral
the mutation dosnet help or hurt the species
what can many mutations be repaired by
enzymes
can mutations be benefial
yes
whats point mutation
changes in a single nucleotide
what are the types of point mutations
substitutions, insertions, deletions
which mutation only affect 1 amino acid
substitution
which types of mutations are more severe
insertions and deletion
what happens in substitution
one letter in a gene is switched out
what happens in insertion
a letter is inserted in a gene
what happens in deletion
a letter is removed from a gene
what is a frame shift mutation
a mutation that changes the reading frame
what does frame shift mutation affect
the whole sequence
which mutations are frame shift
insertion and deletion
