molecular genetics Flashcards
parts of dna
deoxyribose sugar
organic nitrogenous base (ATCG)
phosphate group
structure of dna
double helix
2 nucleotide polymer strands running in anti parallel directions
func of dna
hereditary material responsible for passing genetic info from cell-to-cell or gen-to-gen
structure of dna: specific sequence of bases
info in the form of codes to synthesise proteins
structure of dna: long
stores more info
structure of dna: double helix
provide stability
structure of dna: base pairs held by h bonds
easy unzipping for replication of info
def genes
segment of dna
contains info to make specific polypeptides
triplet code
3 nucleotides in a gene form a codon, each codon codes for 1 amino acid
def mutation
a sudden random change in the structure of a gene/in the chromosome number or structure
albinism
partial/complete loss of pigmentation of skin, eyes, hair
affects production of melanin
down’s syndrome
47 chromosomes instead of 46
genetic condition that causes lifelong mental retardation, developmental delays
sickle cell anemia
alters the message by gene that produces haemoglobin, producing haemoglobin s
rbcs have abnormal rigid sickle shape
less efficient in carrying oxygen, tend to get stuck tgt, blocking smaller capillaries, reducing rate of blood flow
dna replication
semi conservative
2 dna molecules from 1 original dna molecule
rna vs dna
single vs double
5 carbon sugar (ribose) vs deoxyribose
AUCG vs ATCG
trna
carries aa to ribosomes, arranges them along mrna where they are linked by peptide bonds to form proteins
specific for aa it binds
mrna
single stranded
transfers genetic info necessary for protein synthesis from dna in nucleus to ribosomes in cytoplasm
synthesised in nucleus
bases arranged in triplets which direct formation of proteins by ribosomes
rrna
proteins imported from cytoplasm assembled w rrna into large + small ribosomal subunits
location: dna replication vs transcription vs translation
nucleus nucleus cytoplasm
template: dna replication vs transcription vs translation
dna dna mrna
product: dna replication vs transcription vs translation
dna mrna polypeptide
def genetic engineering
manipulation of organism’s genetic material
involves transfer of genes from 1 organism to another
result: transgenic animal/plant
involves use of vector molecule eg plasmids
def plasmids
circular
double stranded dna
separate from chromosomal dna
capable of replicating independently from chromosomal dna
def sticky ends
single stranded sequence of dna bases found on cut end of gene
bases can pair w complementary bases to form double strand
hold 2 pieces of dna together so they can be sealed by dna ligase