Proteins and Enzymes

Properties of Organic molecule depend on

• size and shape of carbon skeleton

• groups of atoms that are attached to the skeleton

What differs only in groups of atoms

sex hormones, testosterone, and estradiol(estrogen)

Four major categories of macromolecules

• carbs

• lipis

• proteins

• nucleic acids

Structure of Carbs

C, H, O and usually in ring form

structure of nucleic acids

C, H, O, N, P

structure of proteins

C, H, O, N, S(most of time)

structure of lipids

C, H, O(few oxygen)

Number of different proteins in human body

more the 100,000 different proteins

Protein function

involved in nearly every dynamic function in the body

How do amino acids link together

through dehydration reactions which form peptide bonds

what determines the proteins function

the protein’s shape

Proteins consist of

polypeptide chains folded into unique shape

what causes shape to form

amino acid sequence

what makes the polypeptide unique

R group

what happens when polypeptides unravel

protein loses its function

Primary Structure

sequence of amino acids

Secondary strucutre

primary structure folds back on itself

Tertiary structure

secondary structure folds and interactions between R groups create the tertiary structure

Quaternary structure

some proteins have more than one polypeptide

2 types of folds

alpha helix(spiral), pleated sheet

How do amino acids interact

through hydrogen bonds

hydrogen bonds

attractions between opposite charges

Enzymes

proteins that speed up reactions in cells

catalyst

speeds up rate of reaction without being consumed

what will catalysts not do

make a reaction happen that wouldn’t naturally

Enzymes & Catalysts

all enzymes are catalysts but not all catalysts are enzymes

activation energy barrier

energy required to start chemical reaction(enzyme lowers energy barrier)

how does enzyme make the reaction

reacts with substrate in the active site of the enzyme

active site

area in enzyme where the substrate fits

Reocurring enzyme reactions

enzymes can react over and over in same type of reaction but not in other reaction

Induced fit

substrate fits into the active site and then the enzymes hugs the substrate even tighter for a more secure fit

Denaturation

enzyme unfolds all of its levels

process of denaturation

• unravels

• loses shape

• loses function

How can protein be denatured

change in salt concentration, change in pH level, high heat

What happens when protein unfolds

activation site is changed so substrate can’t fit and reaction won’t happen