B6: DNA + PROTEIN SYNTHESIS Flashcards
What is a gene?
a small section of DNA on a chromosome
What do genes do?
each gene codes for a particular sequence of amino acids to make a specific protein
What are the base pairings?
A-T (adenine - thymine)
C-G (cytosine - guanine)
How many bases code for 1 amino acid?
a sequence of 3 bases
What is genome?
the entire set of genetic material in an organism
What is the human genome project?
human genome studies and mapped out complete human genome
What makes DNA a polymer?
it is made up of repeating units of 4 different nucleotides (monomers)
What is a triplet codon?
sequence of 3 bases that code for a particular amino acid
What do non-coding parts of DNA do?
they switch on and switch off genes
How would a mutation in non-coding parts of DNA affect gene expression?
the non-coding parts of DNA wouldn’t be able to switch genes on and off
Protein synthesis
-the 2 strands of DNA pull apart from each other and mRNA nucleotides match to their complementary base on the strand
-the mRNA nucleotides are then joined together creating a new strand called the mRNA strand (this is a template of the original DNA)
-the mRNA moves out of the nucleus to the cytoplasm and onto ribosomes
-at the ribosomes the mRNA are read in threes to code for 1 amino acid
-the corresponding amino acids are bought to the ribosomes by carrier molecules (tRNA)
-the amino acids form a chain which then folds when it’s complete to form a specific protein
What are the functions of proteins?
-enzymes (biological catalyst)
-hormones (chemical messengers)
-structural protein (strengthening)
-antibodies (bind to antigens to neutralise antigen/pathogen)
-haemoglobin (combines with O2)
