Proteins-amino acids Flashcards
What are polypeptides made of?
long chains of amino acids linked together by peptide bonds which makes them polymers.
What are proteins made of?
one or more polypeptide chains which have folded into a specific
3D shape.
What are 4 biological roles of proteins?
Structural-main component of body tissues- muscle , skin, ligaments and hair.
Catalytic-all enzymes are proteins.
Signalling- Many hormones and receptors are proteins.
Immunological-all antibodies are proteins.
What are amino acids
Monomers of all proteins , all amino acids have the same general structure
What elements are proteins composed of
C, H , O and P
Give three functions of proteins
-form structural components of animals(muscles are made of proteins).
-Adopt specific shapes
-Membranes have protein constituents that act as carriers and pores for active transport across the membrane and facilitated diffusion.
Do plants and animals need amino acids to make proteins
Yes
Can animals make all amino acids they need
No , they must ingest some essential amino acids
Can plants make all the amino acids they need
Yes , if they can access fixed nitrogen(e.g nitrate)
What’s fixed nitrogen
nitrogen that has been converted from its gaseous form (N2) in the atmosphere into a form that can be used by living organisms
Draw the general structure of an amino acid
What does an R group stand for
It represents a side chain from the central C atom, its different for each amino acid , it can be a simple H atom(glycine)or a complex ring structure.
Which amino acids don’t end in -ine
The ones with the acidic R group like aspartic acid and glutamic acid.
How can R groups vary
Ph , size and polarity with some being hydrophobic and some being hydrophilic
What’s a peptide bond
A bond formed when two amino acids are joined by a condensation reaction
Is a peptide bond a type of covalent bond
Yes
Do enzymes catalyse all hydrolysis and condensation reactions
Yes
What’s the difference between a peptide bond and a dipeptide molecule
A peptide bond is formed when TWO amino acids join via a condensation reactions forming a dipeptide molecule
Draw the condensation reaction between of two amino acids
Draw the hydrolysis reaction of a dipeptide molecule
