BioChem 2 Tutorial Flashcards
Look at structure and function of proteins
Conversation given by lecturer in tutorial in CNM L4 biochem II
Looking at structure and functions of proteins,
structure of genetic material, mutations and role of nutrition
activity of enzymes
processes of energy production and key enzymes and nutrient cofactors as well as mitochondrial damage.
Amino acids are building blocks of proteins
Formed from element Carbon, hydrogen, oxygen, Nitrogen.
Nitrogen component distinguishes proteins from fats and carbohydrates.
With nitrogen also involved in proteins
N is for nitrogen form part of amino group NH3 Always part of an amino acid
Also each Amino Acid has a carboxyl group
R is side chain gives each amino acid different characteristics
a SIDE CHAIN as we will see will give each AA different characteristics, 20 different AA, so 20 different side chains in our bodies.
These are individual units but we can join them together and we join them together, they become peptides. two join together become dibpeptides, 3 are tripeptides etc
Glutamate, cysteine and Glycine are an example of a tripeptide - Glutatione. its a powerful anti-oxidant
they roughen up their surface by changing what at either end, to do so they lose 2hydrogen and 1oxygen (H20) - we call that dehydration synthesis. By taking these out, it means they can stick together to form a peptide bond
R side chains respond differently in nature, like acidic side chains. Remember pH, it’s all about hydrogen ions, when we measure acid, we measure the amount of hydrogen ions. These acidic side chains can release those hydrogen ions, they dont just release them, it depends on the environment.
AA that have alkaline side chains, can bind to hydrogen ions, they can mop them up. so that releasing of, or binding to hydrogen ions, will change the structure of how AA function. eg., ceviche, lemon juice on raw fish, acidic environment. denatures, go from soft and translucent to firm and opaque to firm and opaque. denatured due to pH interaction. we dont kill bacteria or parasites , it just changes structure and therefore function of amino acids.
Amino Acid types - Non-polar amino acids
Sometimes we have more protons in one side of the molecule than at the other side (protons are positively charged)
they’ll be more attracted to the end that has more proteins in the centre which means that end will have more negative charge and the other end will have less negative charge - so that makes a molecule polar, so AA can be polar or non-polar, that doesnt happen when you have an even spread of electrons on the outside.
Non-polar amino acids are hydrophobic, they dont like water. Sometimes we have more molecules on the acidic side than other times. When electrons are whizzing around, that end will have a slightly more negative charge and the other end will have a less negative charge. that makes a molecule polar or nonpolar so AA can be polar or non-polar, depending.
polar amino acids
are hydrophylic, dont mind water, go to the outside, that affects the shape that forms. that’s why different AA form different shapes in our body when they join them together
Nucleic Acids are largest molecules in body STORE genetic info
DNA and RNA , prob heard of them.
DNA is beautiful spiral structure that we have in every cell in our body, holds our genetic info
both are nucleic acids, made of nucleotides, consist of
phosphate group
a sugar and
a nitrogenous base
2m long, carry pattern or recipe (gene) from one generation to the next.
RNA copies it and completes it into a protein structure
20,000-25000 genes in human genome
The nucleotides in DNA have 5-carbon sugar ‘deoxyribose’
DNA has 4possible NUCLEOTIDE BASES
(amino acids)
Adenine (A) - a purine
Cytosine (C) -
Guanine (G) - a purine
Tymine (T)
RNA
is a single strand of NUCLEOTIDES - contains the sugar RIBOSE
RNA copies ONLY HALF because of how the copy happens. Called transcription.
unzips it and changes one of the Nucleotides ‘U’ (only get it with RNA), it attracts amino acids to it, happens in ribosomes in the cell. form a peptide, fold up to make a specific shape called translation.
Genetics
Telemeres at end of DNA, ageing makes them shorten.
exercise and healthy lifestyle helps lengthen.
When we run out of telemeres, our time runs out so very important
Mutation
change in DNA sequence, sometimes different shape with different no protein support.
eg. haemophilia, sickle cell
cancer, chronic stress.
Functions of proteins
not just about muscles, proteins have many more functions so when denatured, can affect lots of activities in the body.
sometimes that’s harmful, other times, doesnt matter.
Lock ‘n key mechanism, specific shape so your key can fit it.
Heavy metals can change their shape and interfere with fundamental functions in the body.
THIS IS A WORK IN PROGRESS
I’m following the lecturer’s video on CNM L4 tutorial, but only 16m33secs into the tutorial. Feel free to help complete this card deck.
RNA copies subsections of those
translates it into an actual protein structure that then becomes parts of your body.
DNA is made of nucleotides X$
A C G T
adenine
cytosine
guanine
thymine
A always to T
C always to G