Proteins and Enzymes Overview

Proteins' Elements

carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur

Protein Monomers

Amino acids

Protein Polymers

Polypeptides

Number of Amino Acids

20 different amino acids

Dehydration Synthesis

A chemical reaction where water is removed to bond molecules

Primary Structure

Linear sequence of amino acids in a protein

Secondary Structure

Folding of the primary structure due to hydrogen bonds forming between the chain of amino acids; Either an alpha helix or beta pleated sheet.

Tertiary Structure

Folding of the secondary structure by interaction of the R groups; 3D structure of folded protein

Quaternary Structure

Two or more proteins (tertiary structures) joined together

Fibrous Proteins

Polypeptide chains arranged as strands or sheets; providing structural support

Globular Proteins

Polypeptide chains folded into compact, rounded shapes

Sickle Cell Anemia

Result of misfolding of hemoglobin protein

Factors Affecting Protein Structure

Changes in DNA sequence, pH, temperature, or salt concentration

Activation Energy

Energy required to start a chemical reaction

Enzymes

Biological catalysts that speed up reactions without being consumed

Enzyme Activation Barrier

Energy barrier enzymes help overcome for reactions to proceed

Enzyme Active Site

Region where substrate binds and reactions occur

Cofactors

Inorganic helpers like iron, zinc, and copper for enzyme function

Coenzymes

Organic molecules aiding enzyme function

Inhibitor

Chemicals hindering enzyme activity

Competitive Inhibitors

Block substrates from binding to the enzyme's active site

Non-Competitive Inhibitors

Bind elsewhere on the enzyme, altering its shape

Feedback Inhibition

Product of a pathway inhibits an enzyme to regulate the pathway

Enzyme Inhibitor Example

Aspirin inhibits prostaglandins to reduce pain and inflammation