Proteins/Protein synthesis Flashcards
What are amino acids?
monomers from which proteins are made
How many different amino acids are there? How do they differ?
20
differ by R group
What are amino acids solubility?
soluble
What is the general structure of an amino acid?
H2N-RCH-C=O-OH
What are the two groups that make up an amino acid?
amine group = NH2
carboxyl group = COOH
How is a dipeptide formed?
condensation reaction between two amino acids forms a peptide bond
How are polypeptides formed?
condensation of many amino acids
How can a dipeptide be broken?
hydrolisis
What two substances are formed when two amino acid molecules join together?
water
dipeptide
How will the change in the primary structure of a globular protein may result in a different three-dimensional structure?
sequence of amino acids changes
tertiary structure changes / folds in a different way
bonds form in different places
What is the role of RNA polymerase in transcription?
join / attach nucleotides to form phosphodiester bonds
How may substitution mutation affect a polypeptide?
no change to sequence of amino acids if degenerate codon / same amino acid coded for
Change in sequence if codes for different amino acid therefore folding / shape / tertiary structure / position of bonds may change
What is the biochemical test for a protein?
Add Biuret solution
turn form blue to purple
Describe the differences between DNA and RNA
DNA is double stranded, RNA single stranded
DNA has thymine present, RNA has uracil present
DNA is longer, RNA is shorter
DNA has deoxyribose sugar, RNA has ribose sugar
DNA stays in the nucleus, RNA leaves the nucleus
Describe the part played by RNA in protein synthesis
carries coded information about the sequence of amino acids copied from DNA
Code is in sequence of bases where a codon codes for one amino acid
Moves out of the nucleus and goes into the cytoplasm to the ribosomes
Describe the role of tRNA in the process of translation
anticodon complementary to codon
tRNA carries the specific amino acid to the ribosome
which forms the correct sequence of amino acids along polypeptide
What factors may increase the frequency at which a mutation in DNA occurs?
high energy radiation - xrays
high energy particles - alpha/beta
chemical mutagens: benzene, caffeine, pesticide
What is a genome?
all DNA of an organism
What is a proteome?
all proteins that can be made in an organism
What is the process of transcription?
DNA Helicase splits DNA
free RNA nucleotides position opposite complementary pairs
makes mRNA
Use RNA polymerase to join free nucleotides (3’ to 5’)
What does transcription result in eukaryotic cells?
pre-mRNA which is spliced to form mRNA
What does transcription result in prokaryotic cells?
directly in the production of mRNA form DNA
What is post transcriptional modification?
pre mRNA is spliced
introns are non-coding
spliceosomes remove introns
make mature mRNA
What is the process of translation?
H bonds form between codon + anticodon
amino acids carried on tRNAs
amino acids joined by peptide bonds
tRNA with complementary anticodon is attracted to codon on mRNA
two tRNAs can sit next to each other
when stop codon reached, polypeptide chain, tRNAs and mRNA all detach from ribosomes
