Proteins

Question 1

what is and are the functions of protein

Answer 1

Most structurally & functionally diverse group of biomolecules​

all proteins are composed of amino acids

Function:​

involved in almost everything ​

enzymes ​

structure (keratin, collagen)​

carriers & transport (membrane channels)​

receptors & binding (defense) ​

contraction (actin & myosin)​

signaling (hormones)​

storage (bean seed proteins)​

Question 2

what are the 3 main functions of protein

Answer 2

Provide structural support (elastin, collagen in cartillage and bone, muscle cells),

movement (actin and myosin in muscle cells)

and metabolic functions

Question 3

What are the metabloc functions

Answer 3

Enzymes: biochemical catalysts that speed up bioochemical reactions. crucial to life

Antibodies: proteins of your immune system that fight disease

Transport: Hemoglobin is a protein that transports oxygen in your blood. Proteins in cell membranes act as channels for molecules entering or leaving the cell

Hormones: many hormones, like insulin, are porteins. Hormones control many aspects of homeostasis

Question 4

what are the building blocks of protein

Answer 4

amino acids (the monomer)

Question 5

how are amino acids joined together

Answer 5

through dehydration synthesis and these bonds are called peptide bonds (C-N)

Question 6

Peptide bonds are polar bonds what are the different bonds

Answer 6

Dipeptide: two amino acids joined together​

Polypeptide (abreviation = ppt): >2 amino acids joined together. ​

Protein: a polypeptide chain becomes a protein after it bends & folds to become functional​

​

Question 7

What arew the 4 levels of organization for protein

Answer 7

Primary, Secondary, Tertiary, quaternary

Question 8

What is Primary structure

Answer 8

PRIMARY STRUCTURE: the sequence of a.a.’s joined together in a line. ​

aa sequence peptide bonds
determined by DNA

Question 9

What is secondary structure

Answer 9

H-Bonding routinely occurs between amino acids in the primary line. ​

this can cause the chain to coil up into a shape called an alpha helix or ​

into layers called beta-pleated sheets​

H bonds adjacent aa

Question 10

what is tertiary structure

Answer 10

R groups, hydrophobic interatctions, disulfide bridges

different types of bonding (covalent, ionic, hydrogen) between -R groups makes the alpha helix bend and turn, forming “globs” of protein of all shapes. ​

This three-dimensional arrangement of the amino acid chain is called the “tertiary structure.” ​

“whole molecule folding”​

Although it may look randomly formed, the final 3-D shape is very exact and precise. ​

The shape is due to the original sequence of amino acids (the primary structure), as this is what will determine which amino acids in the chain will bind with each other, and in what way. ​

Question 11

what is quaternary structure

Answer 11

multiple polypeptides, hydrophobic interactions

association of two or more polypeptide chains​

Not all proteins reach this level of organization​

for proteins with more than one polypeptide chain, the quaternary structure is the specific arrangement of polypeptide chains in that protein. ​

e.g. hemoglobin: this is the O2 carrying protein in blood – made of four polypeptide chains interlocked in a specific way). ​

Question 12

what are denaturing proteins

Answer 12

changes in temperature or pH, or the presence of certain chemicals or heavy metals, can disrupt the bonds that hold a protein together in its particular shape. ​

If a protein is DENATURED, it has lost normal structure/shape because normal bonding between -R groups has been disturbed.​

Question 13

what are the causes of denaturing proteins

Answer 13

raising the temperature above 50C will reliably denature most animal enzymes (e.g. heating an egg)​

changing the pH (eg adding vinegar to milk - since vinegar is an acid it will “curdle” the milk)​

adding heavy metals (eg lead and mercury are “poisons”)​