Proteins Flashcards
Water Soluble Proteins
Non-polar amino acids tend to move towards the center of the molecule which maximizes hydrophobic interactions between amino acids to stabilize the molecule
Polar amino acids tend to move towards the protein surface which maximizes hydrogen bonding
How many Sequences relating to Amino Acids
For every polypeptide with n amino acids, there are 20^n possible sequences
Amino Acid Basic Structure
Amine Group
Carboxyl Group
Carbon in the middle which bonds
with Hydrogen Atom
R Group which is specific to each amino acid (20 R Groups correspond to 20 Amino Acids)
The 4 Protein Structures
Primary
Secondary
Tertiary
Quaternary
Storage of Carbohydrates, Fats and Proteins
Carbohydrates and Fats: Can be stored
Proteins: Can’t be stored
Explain Tertiary Protein Structure
3D because of protein folding, and is stabilized by intramolecular bonds that form between amino acids’ R groups.
Amino acids include:
Hydrogen Bonds
Disulfide Bonds
Ionic Bonds
Hydrophobic Interactions
Temperature in Denaturation
High temperature disrupts the hydrogen bonds that hold the protein together, thus when the bonds break down the protein unfolds and loses its function
Condensation Reaction
The formation of two amino acids forming a dipeptide, but removes water to form peptide bond.
Explain Secondary Protein Structure
The polypeptide chains are coiled or pleated into different shapes:
Alpha Helix: A helical 3D shape
Beta-pleated Sheet: Parallel sections of polypeptide chains that run in opposite directions
Hydrolysis Reaction
Hydrolysis breaks dipeptide down into 2 amino acids, but uses water to split
The 7 Proteins and their Functions
Hemoglobin: Transport
Actin and Myosin: Muscle contraction
Rubisco: Enzyme
Immunoglobulins: Immunity
Rhodopsin: Receptor
Insulin: Hormonal
Collagen: Structural
Explain Primary Protein Structure
A sequence of amino acids in a polypeptide molecule.
It is specific, predictable, and repeatable.
Its precision determines the 3D structure and function
Denaturation
A permanent irreversible change in the 3D structure of a protein that results in the loss of their natural function
Globular Protein Features
Rounded
Functional role
Soluble in water
Irregular amino acid sequence
Elements of Carbohydrates, Fats and Proteins
Carbohydrates and Fats: CHO
Proteins: CHONS
Simplest Unit of Carbohydrates, Fats and Proteins
Carbohydrates: Monosaccharides
Fats: Fatty Acids and Triglycerides
Proteins: Amino Acids
Origin of Carbohydrates, Fats and Proteins
All of them are plant
Fibrous Protein Features
Long and narrow
Structural role
Insoluble in water
Repetitive amino acid sequence
Solubility of Carbohydrates, Fats and Proteins
Carbohydrates: Only sugars are soluble
Fats: Low solubility is soluble
Proteins: Some are soluble
Membrane Bound Proteins
Non-polar amino acids tend to connect themselves in the membrane away from water which creates a stable environment within the membrane
Polar amino acids are found on the aqueous environment inside and outside the cell which facilities the stability of the protein
Rubisco and Function
Has a rounded shape that is tertiary, which provides three dimensional active site where a substrate can bind
The prosthetic group can be a metal ion
Explain Quaternary Protein Structure
Two or more polypeptide chains join to form a protein
Difference with a Conjugated and Non-conjugated Protein
Conjugated: Combined an inorganic component called a prosthetic group
Non-conjugated: Made of polypeptide chain that is not associated with other chemical groups
pH in Denaturation
Changing the pH affects the ionic bond between opposite charges of non-adjacent amino acids, which will alter protein shape
Changes in pH also affect the strength of the hydrogen bond
Bond of Carbohydrates, Fats and Proteins
Carbohydrates: Glycosidic Bond
Fats: Ester Bond
Proteins: Peptide Bond
Difference with Essential and Non-Essential Amino Acids
Essential: Can not be synthesized in the body and must be included in diet
Non-Essential: Can be synthesized in the body from other amino acids
Protein Elements
CHONS
Carbon, Hydrogen, Oxygen, Nitrogen, (Sometimes) Sulfur
Hemoglobin and Function
Transport protein
Made of 4 polypeptide chains and has 4 heme prosthetic groups
Each heme group binds to oxygen and transports it with the red blood cell
Insulin and Function
Made of two polypeptide chains linked by disulfide bonds which is quaternary
Its shape allows it to bind to insulin receptors to regulate glucose uptake
Collagen and Function
A fibrous protein made from 3 polypeptide chains held closely by covalent and hydrogen bonds to form a triple helix
Forms the main structure in tissues such as skin, blood vessels and ligaments
Quaternary
