HL- 7.3: Transcription

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Terms in this set (...)

start codon
AUG
start codon name
methionine
stop codons
UGA, UAG, UAA
the nucleotide sequence at the 3' end of tRNA
CCA
the large subunit of the ribosome connects ? to form the
translation initiation complex
phase where amino acids are added to the polypeptide chain
the elongation phase
this is where the tRNA bring amino acids to the ribosome
mRNA ribosomal complex
these help the tRNA to bind the mRNA
elongation factors
each tRNA goes from the ----- to the ----- site
P and E
translocation phase
the tRNA moves from site A to P to E in a 5' to 3' direction
phase where stop codon arrives A
termination phase
this ends the polypeptide chain
release factor
ribsomes are constructed in the ------ of eurkaryotic cells
nucleolus
Site A
holds the tRNA holding the amino acid that will be added next to the polypeptide chain
Site P
holds the tRNA carrying the growing polypeptide chain
Site E
site from which the tRNA that has lost its amino acid is discharged
The genetic code is degenerate
for each amino acid there may be more than one codon
the genetic code is universal
all organisms share the same code
the code at the site of the amino acid attachment
CCA
when the amino acid is attached to the tRNA using ATP
activated amino acid
translation initiation complex
hydrogen bonded initiator tRNA and start codon and ribosomal subunit
elongation phase
tRNAs bring the amino acids to the mRNA-ribosomal complex in the order specified by the codons in the mRNA
elongation factors
these aid in the binding of tRNAs to the exposed mRNA codons at the A site
translocation phase
movement of the tRNA's from one site of the mRNA to another
termination phase
- one of the 3 stop codons appears at the open A site
-a protein called the release factor fills the A site
- it frees the polypeptide with hydrolysis
haemoglobin
a protein carrying iron that transports oxygen from the lungs to all parts of the body in vertebrates
actin and myosin
proteins that interact to bring about muscle movement in animals
insulin
hormone secreted by the pancreas that helps maintain blood glucose levels in many vertebrates
immunoglobulins
a group of proteins that act as antibodies to fight bacteria and viruses
amylase
a digestive enzyme that catalyses the hydrolysis of starch
primary structure
-unique sequence of amino acids
-a chain of amino acids attached by polypeptide bonds
- determines the next 3 levels of protein organization
secondary structure
-hydrogen bonds between oxygen from the carboxyl group of one amino acid and a hydrogen from an amino group of another
alpha-helix
beta-pleated sheet
tertiary organisation
- the polypeptide chain bends and fold itself because of reactions between R groups and the peptide backbone
interactions that cause tertiary organisation
-covalent bonds between sulfur atoms to create disulphide bonds
-hydrogen bonds between polar side chains
-Van der Waals interactions between hydrophobic side chains of amino acids
-ionic bonds between positively and negatively charged side chains
quaternary structure
- multiple polypeptide chains form a single structure
-
non-polypeptide
prosthetic
conjugated protein
proteins that contain prosthetic groups
haemoglobin consists of
- 4 polypeptide chains each containing a non-polypeptide group called a haem
-haem contains an iron atom that binds to oxygen
fibrous proteins
-composed of many polypeptide chains in a long, narrow shape
-usually insoluble in water
collagen
fibrous protein that plays a structural role in the connective tissue of humans
globular proteins
three-dimensional and are water soluble
examples of fibrous protein
actin and collagen
examples of globular protein
haemoglobin and insulin
amino acids with non-polar side chains are
-hydrophobic
-found in the region proteins that are linked to the hydrophobic area of the cell membrane
polar amino acids are
-hydrophilic
-found in the regions proteins that are exposed to water