2.4 proteins

state the elements proteins are composed of

1. hydrogen, carbon, oxygen
2. nitrogen, sometimes sulphur

what link together to form polypeptides, proteins?

amino acids

outline the role of condensation in the formation of polypeptides

amino acids are linked together by condensation reactions to form polypetides -> water is also produced

how many different amino acids are used by organisms to synthesize polypeptides (1)

20

what makes each of the different amino acids unique?

the R group

where in cells does protein synthesis occur?

on ribosomes

describe how the amino acid sequence of a polypeptide is determined and why this sequence is important

sequence is coded for by a gene -> can be linked together in any sequences, resulting in a huge range of polypeptides -> the sequence of the amino acids determines the 3D confrimation and therefore the function of the protein

outline what is meant by 'amino acids and the genetic code are nearly universal'

the same 20 amino acids are used by most living organisms to build polypeptides -> coded for by the same genetic code

define: proteome

entire set of proteins produced by a cell/organism

identify the charateristics of R groups that may influence the structure of a protein

polar or non polar -> positively/negatively charged

define: primary structure

number and sequences of amino acids in a polypetide

types of bonds/ significant info in a primary protein

peptide bonds
determines the type/function of a protein, as well as subsquent levels of structure

define: secondary structure

regular folding/spiraling of a polypeptide

state the type of bonds, examples and other significant information regarding a secondary protein

hydrogen bonds
beta-pleated sheets, alpha helixes
in many proteins only some of the polypeptide form secondary structures, others do not
in a few almost all of the polypeptide does, and in some these structures do not form at all

define: tertiary proteins

the further folding of the polypeptide, which determines its 3D confirmation

what bonds are present in a tertiary protein

DIHH
Disulfide Bonds
Ionic Bonds
Hydrogen Bonds
Hydrophobic Interactions

Give examples and any significant information regarding tertiary proteins

enzyme loyoszyme
sig info: determines whether the enzyme is globular/fibrous, shape of active site of enzyme

def: quaternary structure

linking of polypeptides to form a single protein

name the type of bonds, an example of and any other signifcant information of quarternary protein structure

DIHH bonds
hemoglobin
may also involve the linking together of a prostethic group in some proteins

State why the structure of a protein is important

the structure of the protein determines its function

define: denaturation

structural change in the 3D confirmation of a protein, that results in loss of biological properties

describe effects of heat on protein structure

heat will cause a protein to denature above its optimum temperature -> due to increased vibrations within the protein, which break the intramolecular bonds that stablize its conformation -> changing its conformation

describe effects of deviation from optimum pH on protein structure

deviation from optimum pH will cause protein to denature -> due to gain/loss of hydrogen ions, which breaks the intramolecular bonds that stablize its conformation -> changing its conformation

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