2.2.8 proteins 1: amino acids Flashcards
amino acids
monomers of all protein & all amino acids have same basic structure
peptide bond
bond formed when 2 amino acids are joined by condensation reaction
properties of proteins & what function this allows
- form structural components (particularly animals) eg. muscles made of proteins
- tendency to adopt specific shapes makes proteins important as enzymes, antibodies & some hormones
- membranes have protein constituents that act as carriers/pores for active transport across membranes & facilitated diffusion
which amino acids are ingested by animals (& not made)
essential amino acids
what do plants need to be able to make their necessary amino acids
access to fixed nitrogen (eg. nitrate)
which elements do all amino acids contain & which element do some contain
all: carbon, hydrogen, oxygen & nitrogen
some: sulphur
how many amino acids are proteinogenic (out of 500)
20
proteinogenic
amino acids found in proteins
structure of amino acids
- each protein chain of amino acids has:
- amino group (NH2) at 1 end
- carboxyl group (-COOH) at other end
- R group = diff. in each amino acids
what can R groups vary in
- size
- polarity
- charge
- some hydrophilic/some hydrophobic
what are amino acids joined by
a covalent bond called a peptide bond
what’s involved to make/break a peptide bond
make = condensation reaction
break = hydrolysis reaction
which enzyme breaks peptide bonds in the intestines during digestion
- what does this enzyme also break down
protease
- also breaks down protein hormones so effects not permanent
name for 2 amino acids joined together
dipeptide
what’s a polypeptide
long chain of amino acids
