B1.2 Proteins Flashcards
What is the generalised structure of an amino acid?
All amino acids have the same structure in terms of an amine group and carboxyl group
BUT different variable groups (R groups)
draw the generalised structure of an amino acid + label the amine group, carboxyl group, and R group
what is a dipeptide?
a peptide made up of two monomers
OR
a molecule consisting of two amino acids joined by a single peptide bond.
what is a oligopeptide?
An oligomer of amino acid units joined by peptide linkages and whose molecules contain a relatively small number of amino-acid residues
(a short chain of amino acids)
what is a polypeptide?
a peptide made up of many monomers
OR
long chains of covalently bonded amino acids
draw peptide bond formation in a condensation reaction between two amino acids
- two amino acids are joined in a condensation reaction via the carboxyl group of one amino acid and amine group of other, creating a peptide bond and water
where in the cell does polypeptide formation occur?
a polypeptide is made on a ribosome via translation. they are formed when amino acids are joined together
Compare the source of amino acids by plant and animal cells
Plants get it from photosynthesis while animals from consuming plants or other animals
Define “essential” and “non-essential” as related to dietary amino acids
- Essential can’t be synthesized from the body; it gets it through diet
- Non essential can produce it on its own
why do vegan diets require attention to food combinations to ensure essential amino acids are consumed?
Because some plants lack specific amino acids, so they must create a balanced diet by giving more attention to food combinations
there is _____ of DNA base sequences
there is a limitless diversity of DNA base sequences
why is there a limitless diversity of DNA base sequences?
Because the four nucleotide bases (A, T, C, G) can be arranged in virtually limitless combinations.
These sequences code for proteins by specifying the order of amino acids in a peptide chain.
With 20 different amino acids and the possibility of arranging them in any order, this results in an almost infinite variety of unique proteins
the structure of protein has ___ levels. what are they?
it has 4 levels:
- primary
- secondary
- tertiary
- quaternary
what makes a substance acidic?
Hydrogen (H+) ions
What makes a substance alkaline?
Hydroxide (OH-) ions
Each of the 20 amino acids consists of?
an alpha carbon atom attached to an amine group, carboxyl group, H atom and an R-group
Each of the 20 amino acids has a ____ R-group, providing it with ____
Each of the 20 amino acids has a unique R-group, providing it with its unique structure
Amino acids join together to make a protein through _______
When amino acids join together, ____ are formed.
Amino acids join together to make a protein through condensation reactions
When amino acids join together, peptide bonds are formed
Essential amino acids are amino acids that your body _____ while non-essential amino acids ______
Essential amino acids are amino acids that your body cannot synthesise while non-essential amino acids can be produced by the body from other amino acids or by the breakdown of protein
the genetic code serves ____
the genetic code serves as a universal language for all living organisms and provides the instructions for protein synthesis
what is denaturation?
it is when extreme pH and temperature causes the breaking of bonds, causing the protein to lose its 3D conformation.
it is a process modifying the molecular structure of a protein, damaging / changing the active site
glycine is?
the simplest amino acid, with a hydrogen atom forming its R group
Name the monomer of proteins and draw its general structure
Amino acids.
- Name the reaction that takes place in the formation of a dipeptide
- name the bond formed.
- a condensation reaction
- a peptide bond
What is the primary structure of a protein?
The sequence of amino acids in the polypeptide chain.
Name two features of the secondary structure of a protein.
Alpha helices and beta pleated sheets.
Name three types of bond that stabilize the tertiary structure of a protein
Hydrogen bonds, ionic bonds, and disulfide bridges
Haemoglobin has a quaternary structure. What does this mean?
It consists of more than one polypeptide chain.
Name a biochemical test for proteins.
Biuret test.
What is a prosthetic group? Why are they important in some proteins?
It is a non-protein part of the molecule which helps the functioning of the protein.
explain the effect of pH on temperature on protein structure and function
Extreme pH and temperature can cause the denaturation of a protein as it causes the breaking of bonds, causing the protein to lose its 3D conformation
–> it cannot carry out its function
