Chemistry & Biochemistry 2 Flashcards
(86 cards)
What are the building blocks of proteins?
And how many does the body need to create the proteins needed to function?
Amino acids
The body needs 20
What 4 elements form proteins?
And which one distinguishes proteins (from fats and carbs)?
Carbon, Hydrogen, Oxygen, Nitrogen
Nitrogen distinguishes proteins from fats and carbs.
Describe the structural groups found in amino acids
Along with a Carbon and a Hydrogen, every amino acid has a carboxyl group / acid (-COOH) and an amino group (-NH3)
Each individual amino acid has a side chain (labelled R) that determines it’s characteristic.
What are peptide bonds?
Amino acids join together using dehydration synthesis (removing water) to create peptide bonds.
Dipeptide = 2 amino acids joined with 1 bond.
Tripeptide = 3 joined together with 2 bonds
Name a tripeptide
Glutathione
A powerful antioxidant containing amino acids L-cysteine, L-glutamate, and glucine.
List 3 cysteine rich foods
Legumes
Sunflower seeds
Eggs
What is ceviche and its risks?
This is when lemon juice is put on raw fish - the protein structures change as it is denatured. It changes from soft/translucent to firm and more opaque.
This does not necessarily kill all potential harmful organisms and parasites though.
How much amino acids react to the pH of its surrounding fluid?
The pH of the fluid will affect the 3D structure and therefore it’s function.
Amino acids with acidic side chains can release hydrogens ions depending on the pH. And Amino acids with basic side chains can bind to hydrogen ions again depending on the pH.
Describe how non-polar and polar amino acids behave in water.
Give an example of each.
Non-polar are hydrophobic and so like to be on the inside of the protein.
E.g. tryptophan (used to produce serotonin)
Polar amino acids are hydrophilic and so like to be on the outside of the protein.
E.g. tyrosine (used to create adrenaline)
List 5 functions of protein
- Structure of body tissue
- Movement
- Carrier molecules
- Storage molecules
- Fluid balance
- Enzymes
- Hormones
- Immune function
- Clotting mechanism
- Alternative energy source
- Cell membrane proteins
Describe denaturation
The 3D structure of a protein is key to its function. Denaturation describes the change in a protein’s 3D structure which results in it no longer functioning correctly.
What can denature a protein?
- Heat
- pH change
- Heavy metals e.g. lead and mercury
How does the body digest proteins from consumption to the stomach?
Uses enzymes to help break the peptide bonds between amino acids.
Mechanically broken down in the mouth, increasing surface area.
Chemical digestion begins in the stomach, the enzyme pepsin breaks down long chains.
NB Pepsin is initially released as pepsinogen. The presence of HCI converts it to pepsin. Pepsin needs to be a pH2 to function correctly. So adequate stomach acid is critical for digestion
Describe how proteins are digested and absorbed after passing through the stomach.
Once in the small intestine, the hormone CCK is released , triggering release of pancreatic juices.
Pancreatic juices contain proteases called trypsin and chymotrypsin. These further break down the proteins before they can enter the blood.
What are Nucleic Acids?
The largest molecules in the body and used to store genetic information.
Deoxyribonucleic acid (DNA)
Ribonucleic acid (RNA)
What are the building blocks of nucleic acids?
They’re called nucleotides. Consisting of a phosphate group, sugar, and a nitrogenous base.
List Describe the different roles of DNA & RNA
DNA stores all the genetic information - it acts as a template for protein synthesis.
RNA is used to copy specific sub-sections of DNA called ‘genes’ and translate them into proteins.
What are the ends of sections of DNA called?
Telomeres
What are the 4 nucleotide bases?
And what are they made from?
Adenine - purine
Thymine - pyrimidine
Guanine - purine
Cytosine - pyrimidine
These are all 5-carbon sugars called deoxyribose
Briefly describe the role of RNA
RNA is a single strand of nucleotides which contain the sugar ‘ribose’.
A molecule of mRNA copies the gene in DNA. This is known as transcription.
mRNA then travels to a ribosome where it is translated and the ribosome can produce the protein.
Describes the bonds that hold DNA together
DNA has 2 strands wound together.
The 2 strands are held together by hydrogen bonds in the middle.
The bonds along the sides are covalent bonds.
NB as hydrogen bonds are much weaker, this is how DNA is able to ‘unzip’ itself for protein synthesis.
What happens to DNS during aging?
And what can accelerate this process?
The length of the telomeres is shortened as cells and tissues age.
Accelerated by stress, poor nutrition, poor sleep, chemical agents, lack of exercise.
What herb can support healthy aging and how?
Gotu kola - by reducing telomere shortening
How might mutations in DNA affect proteins?
Changes in the DNA code will ultimately affect the synthasis of proteins. Mutations can change the sequence of amino acids in the protein, changing their shade and potentially making them faulty