proteins

Question 1

What are amino acids?

Answer 1

amino acids are the monomer of protein. they join together, to form polypeptides. there are 20 different amino acids.

Question 2

what are peptide bonds?

Answer 2

amino acids are covalently joined together by peptide bonds, to form polypeptide chains. this requires a condensation reaction. the sequence of amino acids, is encoded by genes, and the assembly of the polypeptide chain occurs in the ribosome.

Question 3

functions of proteins acronym: SHITSME

Answer 3

S-structure (collagen, spider silk)
H- hormonal (insulin, glucagon)
I- immunity (immunoglobulins)
T- transport (hemoglobin)
S- sensation (rhodopsin)
M- movement (actin, myosin)
E- enzymatic (rubisco, catalase)

Question 4

what is denaturation?

Answer 4

it is the structural change in the protein the results in the loss ( usually permanent loss) of its biological properties.
it can be cause by temperature ( the heat breaks the structural bonds), or pH ( alters protein charge, which changes solubility and shape).

Question 5

what are the key components of a general amino acid?

Answer 5

-amino group- covalent bonds, gives the amino acid its basic properties.
-variable group- only thing that changes.
-carboxylic acid group- gives the amino acid its acidic properties.

Question 6

what is the primary structure of a protein?

Answer 6

-two amino acids=dipeptide
-three amino acids=tripeptide
-many amino acids=polypeptide
-the sequence of amino acids in a polypeptide, is the primary structure.

Question 7

what is the secondary structure of a protein?

Answer 7

-the peptide group after each amino acid is polar.
-these groups join together to make hydrogen bonds.
-this is where the protein starts to fold, because the more positively charged hydrogen, is attracted to the more negatively charged oxygen.

Question 8

what are the two types of secondary structure?

Answer 8

1. Alpha helix
   -the polypeptide coils up on itself.
   -the hydrogen bond is formed every 3-4 amino acids.
2. Beta pleated sheet
   -hydrogen bonds formed between aligned regions of a polypeptide chain.
   -aligned regions can be parallel, or anti-parallel

Question 9

what is the tertiary structure of a protein?

Answer 9

-it is the final folding of the protein.
-when the R group starts to form bonds and interact.
-this causes the alpha helices and beta sheets to close together.
-this forms a 3-D protein

Question 10

what bonds are in the tertiary structure?

Answer 10

hydrogen bonds:
-they are weak and easily broken by extreme temperature and pH.
-you get more in the tertiary structure
disulfide bonds:
-covalent bond between the R group of the amino acid cysteine strongest r-group interaction.
-it is resistant to extreme temperature and pH.
charge- charge interaction:
-very strong bond, but sensitive to pH
-ionic bond
-oppositely charges side chains.
hydrophobic interaction:
-between nonpolar hydrophobic side chains
-very weak alone, but can be strong when loads are together.

Question 11

what is the quaternary structure?

Answer 11

the quaternary structure is more than one chain

Question 12

what are the structural features of fibrous proteins?

Answer 12

-they are long and narrow
-they have a structural function
-they are in a repetitive amino acid sequence
-they have hydrophobic side chains making them insoluble in water.
-they are used for strength and support, e.g. keratin for your hair.
-they are more stable than globular proteins.

Question 13

what are the structural features of globular proteins?

Answer 13

-roughly spherical in shape
-they are sensitive to change in temperature and pH
-made if irregular amino acid sequences, with hydrophobic center and hydrophilic side chains, so they are soluble in water.
-they are also functional and involved in catalysts and transport
-e.g. hemoglobin which is what oxygen binds to in the red blood cells.