Proteins Function Structure Denaturation
Proteins Functions Direct and control chemical reactions Structural parts of cell ex. Cell membrane 3. Transport of molecules haemoglobin (O2 transport)
Proteins Function (cont’d) 4. Provide support and shape Muscle/hair/nails… 5. Chemical Messengers Hormones - insulin
Proteins Structure Macromolecule made up of smaller units called amino acids made up of carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and sulphur (S)
Protein Structure Amino Acids humans need 20 different a.a.’s 8 are essential amino acids (our body cannot make them – come from our food)
Protein Structure Protein Structure involves 4 phases beginning with a polypeptide chain and ending with several chains connecting together Primary Structure Individual amino acids join together Many a.a.’s join together to form a polypeptide chain
Protein Structure Secondary Structure When a polypeptide chain grows beyond 30 amino acids, it begins to fold upon itself Forms either a: α-helix β-sheet
Secondary Structure
Protein Structure Tertiary Structure Increasing bonding, cause secondary structure to fold up on itself further Forms a 3-D shape
Tertiary Structure
Protein Structure Quaternary Structure 2 or more polypeptide chains combine to finally form a functional protein
Protein Structure Protein structure depends entirely on the order in which the amino acids come together. Chemical bonds help molecules take and hold a specific shape
Protein formation ** the ultimate shape of the protein will determine its function in the cell/organism.
Protein Denaturation Shapes of proteins are critical to their proper functioning When the protein changes shape it becomes “denatured” Protein loses its ability to perform its specific function
Protein Denaturation Conditions that denature a protein Heat: Cooking, sunstroke, fever pH change: Stomach acid, perm Radiation: Sun (uv rays), x-rays, microwaves, cell phones? Harsh chemicals: Salt – tenderizes meat
Proteins What to do now? Text page 35, #5,-8 Summarize note/mind map