Lecture 6 - Biomolecules Part 2 Flashcards
What are proteins?
Large, complex molecules that do most of the work in cells
required for structure, function, and regulation of the body’s tissues and organs
Amino Acids
What proteins are made up of
How many types of amino acids are there that can be combined to make a protein?
20
Essential Amino Acids
Cannot be made in the body
Semi-Essential Amino Acids
Arginine and Histidine
Can be synthesized by adults but not kids
How are amino acids linked to form proteins?
Carboxyl and amino groups are synthesized through dehydration synthesis. Resulting compound has peptide bonds
Proteins shape is determined by:
The order that amino acids are joined in
Shape determines function
Dipeptide
2 amino acids linked by a peptide bond
Polypeptide
Many amino acids linked by peptide bonds
Protein structure:
One or more ploypeptides folded into a specific 3-dimensional shape
4 Levels of Protein Structure
Primary Structure
Secondary Structure
Tertiary Structure
Quaternary Structure
Primary Structure
Unique Sequence
Secondary Sequence
Hydrogen bonds between amino acids in the polypeptide
Parts of polypeptide coil or fold into a local pattern
Two types of secondary structures
Alpha Helix & Pleated Sheet
Tertiary Structure
Overall 3-dimensional shape of a folded polypeptide
Quaternary Structure
Only in proteins with two or more polypeptides
Overall shape after polypeptides fit together
Lysozyme
Antimicrobial enzyme produced by animals that forms part of the innate immune system
Define Sickle Cell Hemoglobin
Sickled red blood cells are stiff and angular, causing them to become stuck in small capillaries
Denaturation of Proteins
Process in which 3-dimensional shape of polypeptide becomes distorted
Protein no longer functions
Causes of Denaturation
Temperature
PH
Salts
Protein Functions
- Enzymatic
- Structural
- Contractile
- Defensive
- Transport
- Signaling
Protein functions: Enzymes
Enzymes speed up chemical reactions
Protein functions: Structural Proteins
Collagen - makes up bones, tendons, ligaments, skin
Keratin - Makes up hair, nails, claws, hooves, reptile scales
Protein functions: Contractile proteins
Mediate sliding of contractile fibers (Muscles)