4. CHEMISTRY & BIOCHEMISTRY 2 Flashcards
This module covers: • The structure and function of proteins. • The structure of genetic material, mutations, as well as the role of nutrition. • The activity and importance of enzymes, including enzymes found in food and their therapeutic applications. • The processes of energy production and the key enzymes and nutrient cofactors, as well as mitochondrial damage. (145 cards)
What are amino acids?
The building blocks for proteins
What do amino acids consist of?
Carbon, Hydrogen, Oxygen and Nitrogen
How many amino acids are required in the body?
20
How are peptide bonds formed?
Amino acids join together using dehydration synthesis (by removing water) to create ‘peptide bonds’
Every amino acid has
a Carboxyl Group/ acid. (-COOH) and
an amino group (-NH3)
What does each amino acid have that determines its characteristics?
a SIDE CHAIN (labelled R )
PEPTIDES
Amino acids join together using DEHYDRATION Synthesis (by removing water) to create ‘peptide bonds’
What is aspartame?
A harmful example of a ‘dipeptide’ which does not occur in nature and is a neurotoxin. Its manufactured to be an artifical sweetener.
PEPTIDES
Describe the powerful antioxidant Glutathione?
Which foods optimise glutathione production?
A TRIPEPTIDE containing amino acids
L-cysteine,
L-glutamate and
glycine
Cysteine is the most commonly limiting production of G.
Have a good intake of cysteine from:-
Legumes, sunflower seeds and eggs (it’ll optimise G production)
Non-polar amino acids are ?
Hydrophobic
Tryptophan is hydrophobic (used to produce serotonin which stimulates gut motility and digestive juices).
Polar amino acids are?
Hydrophilic
When a protein folds up in a watery env, they like to be on outside of the protein structure, interacting with polar water molecules, include TYROSINE - used to create adrenaline and thyroxine.
It is the combination of P and Non-P AA that ultimately determine the 3D shape of the protein
Amino acids with ACIDIC side chains can RELEASE hydrogen ions - whether they do or not depends on the pH of surrounding fluid
Amino acids with BASIC side chains can BIND to hydrogen ions - whether they do or not depend on the pH of the surrounding fluid.
This means the pH of the fluid the protein is in will affect its 3D STRUCTURE and therefore its FUNCTION
Name four functions of proteins?
- Structure of body tissues, e.g collagen
- Movement e.g Actin and myosin fibres (in muscles)
- Carrier molecules (e.g haemoglobin)
- Storage molecules e.g ferritin (iron)
- Fluid balance in the blood (albumin
- Enzymes (for reactions in the body)
- Hormones e.g insulin
- Immune function e.g. antibodies
- Clotting mechanisms e.g. clotting factors
- Alternative energy source - much less efficient than carbohydrate or fat so only used during dietary deficiency
- Cell membrane proteins e.g. receptors
The 3D structure of a protein is key to its function - If it changes or unfolds, it is denatured. Denatured proteins no longer function correctly , think protein fibres in muscle cells.
How can proteins be denatured?
Heat , cooking egg whites and pH changes (not necessarily bad)
Heavy metals e.g. lead and mercury(they can damage proteins such as hormones, antibodies and enzymes)
Coriander and chlorella remove heavy metals from body
To digest proteins, we use enzymes to break peptide bonds between AA
Can be broken by Hydrolysis reaction - using water
Can be mechanically broken down in mouth increasing surface area for enzymes to work on.
Chemical digestion of proteins begins in the stomach where enzyme PEPSIN breaks down long protein chains.
PEPSIN is released by gastric chief cells (inactive form) as pepsinogen. When HCl is present, it converts it to pepsin.
Pepsin needs pH2 to function correctly so adequate HCl is critical for good protein digestion.
Protein rich CHYME enters small intestine, the hormone CCK is released which triggers the pancreas to release pancreatic juices. They contain ….
proteases called trypsin and chymotrypsin
these shorter protein chains are further broken down into tripeptides , dipeptides and single AA by pancreatic proteases and brush border enzymes.
AA and small peptides are then absorbed into the blood.
What are the largest molecules in the body?
And which are the most common ones?
Nucleic acids and are used to store genetic info
Deoxyribonucleic acid(DNA) and ribonucleic acid(RNA)
the building blocks of nucleic acids are nucleotides which consist of phosphate group, sugar and nitrogenous base
Functions of nucleic acids
DNA stores genetic info and acts like a recipe book
every cell contains 1 DNA molecule to carry from generation to the next.
Human DNA molecules are huge - 2m
DNA acts as template for protein synthesis, RNA is used to copy specific sub-sections of DNA called genes and translate it to proteins.
20,000-25000 genes in the human genome (complete set of DNA).
Nucleotides in DNA contain 5 carbon sugar ‘deoxyribose’
4possible nucleotide bases (AA)
adenine (A) - a purine
Cytosine (C)
Guanine (G) - a purine
Thymine (T)
purine rich foods shellfish, red meat, are metabolised to form uric acid, if in excess, crystallise in joints and cause gout.
What is RNA?
Ribonucleic acid
It is used to copy specific sub-sections of DNA called ‘genes’
DNA has 2 strands wound together called a double helix
2strands held together by hydrogen bonds between the base in middle of ladder, whilst sugar phosphate at the sides of ladder form COVALENT bonds. Hydrogen bonds are weaker , thats how DNA can unzip during protein synthesis.
Adenine pair with thymine
guanine pairs with cytosine
which is important as sequences of these pairs code for production of a certain protein like hormone , say insulin
RNA is single strand nucleotides which contain the sugar ribose.
DNA is double stranded structure and has the sugar DEOXYribose
a molecule of mRNA copies the recipe in DNA (a gene) known as transcription.
Travels to a ribosome where it is read. then coded for a hormone. Called TRANSLATION
Genetics
DNA is used as a manual for making all proteins in the body from muscle tissue to enzymes.
DNA is condensed to form chromosomes. end sections called TELOMERES
The length of telomeres shortens as cells and tissues age. Can accelerate by…
stress,
poor nutrition,
poor sleep,
chemical agents,
lack of exercise,
negative thoughts.
Gotu Kola reduces telomere shortening
so supports healthy ageing