Human Genome Flashcards
Define genome
All the genes in a cell
Define gene
An area/length on a chromosome that codes for a particular protein
Ensures protein has correct/specific function
Define chromosome
Tightly coiled molecule of DNA
Describe the structure of chromatin and chromosomes…
DNA found in nucleus
Tightly wrapped around histones (proteins)- together is chromatin
During cell division becomes further coiled into chromosomes
What is protein synthesis?
Process by which proteins are made from genes
What are the processes involved in protein synthesis?
Transcription, splicing and translation
What is transcription?
Process where a DNA sequence is copied into similar, single stranded molecules- messenger mRNA
Describe the process of transcription?
DNA separates into 2 strands- facilitated by enzyme Helicase that breaks hydrogen bonds between base pairs (unzips DNA)
DNA strand acts as template for mRNA
Free RNA nucleotides align with the DNA bases to form complementary strand (uracil rather than thymine)
RNA nucleotides bonded together along their backbones- forms mRNA strand
mRNA undergoes splicing before leaving nucleus via nuclear pore then enters cytoplasm
Describe the process of splicing…
Introns are removed from mRNA
What are exons?
Regions of that code for proteins
What are introns?
DNA that deist specifically code for proteins
What is translation?
Amino acid chains created on ribosomes with the assistance of transfer RNA
Describe the process of translation…
mRNA strand attached to ribosome found in either the cytoplasm or on RER
Ribosome moves along mRNA strand- AA brought by molecule tRNA according to sequence being read by the ribosome
3 bases code for one AA- triplet sequence is a ‘codon’
tRNA molecule have an anticodon providing complementary base pair arrangements to the codon on mRNA
