chapter one: the relationship between nucleic acids and proteins Flashcards
2 monomers of a nucleic acid
deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)
state the base pairing rules
DNA:
- Adenine and Thymine
- Guanine and Cytosine
RNA
- Adenine and Uracil
- Guanine and Cytosine
compare DNA and RNA
similarities:
- DNA and RNA are both made up of nucleotide monomers, which contain phosphate, a sugar and a nitrogenous base
differences:
- DNA contains thymine as a base instead of uracil
- DNA is double stranded and RNA is single stranded
- DNA is located in the nucleus whilst RNA is everywhere
- DNA has a function of instructing and RNA makes proteins
eukaryotic genes features
consists of a coding region and flanking regions
- coding regions: part of a gene that contains the coded information for making a protein —> within the coding regions, it contains exons and introns
- exons contain the instructions for the synthesis of the protein and are both transcribed and translated —> they provide the instructions that code for the amino acids in the produced protein
- introns are sections that are no expressed
- flanking regions: in the upstream and downstream of a gene
define gene regulation
gene regulation is when genes are regulated to keep them from producing but not overflood the cell with that gene.
- the process of turning genes on and off
compare structural and regulatory genes
structural genes:
- codes for proteins that become part of the structure or function of cells
regulatory genes:
- code for proteins that control the expression of other genes -> their actions determine whether other genes are turned on or off
outline how the trp operon works
presense of trp:
- trp binds to the repressor protein causing a configurational change in its shape → allows it to be active
- enables the repressor to bind to the operator
- RNA polymerase is unable to bind to the promoter and transcription does not occur
- operon is turned off
- trp isn’t made
absence of trp:
- repressor is unable to bind to the operator (in an inactive form)
- rna polymerase can bind to the promoter and start transcription of the structural genes
- operon is on
- trp can be made
define the proteome
the complete array of proteins produced by a single cell or an organism in a particular environment
describe condensation polymerisation
- the process of joining amino acids together
- condensation → water/smaller
- polymerisation → making a polymer
- amino acids join using energy and water is released
- carboxyl groups bind with the amino group
- OH of carboxyl group joins w/ H of the amino group to form water
define polymer
- state 2 molecules fond in living things that are polymers
polymers are what makes up amino acids which makes proteins
- a large substance made up of smaller subunits
describe the 4 levels of protein structure
primary:
- A linear sequence of amino acids linked together called a polypeptide chain
- NOT FUNCTIONAL
secondary:
- consists of alpha helices, beta pleated sheets and random coils
- the folding and coiling is caused by interactions of the R-group
tertiary:
- A irregular 3D folding held together by ionic or hydrogen bonds forming a complex shape
- A FUNCTIONAL STRUCTURE
quaternary:
- bonding of two or more polypeptide chain
explain why the shape of a protein is important to its function
- allows it to have a specific function in a cell or body structure to interact with other molecules
summaries nucleus
codes for the proteins (makes mRNA) which goes to the ribosome on the rough endoplasmic reticulum
summaries rough endoplasmic reticulum
the ribosome uses the mRNA code to make a protein, which is then folded and modifies in the rough endoplasmic reticulum
summaries transport vesicle
the proteins are placed into a transport vesicle and then moves to the golgi apparatus