Lesson Three - Amino Acid, R-Chains and the Peptide Bond Flashcards
What is a Heteropolymer?
A different things/ groups that join together
What are proteins and why?
Heteropolymers as the amino acids which join to create the protein are different
How many human amino acids are there?
20
What type of bonds join amino acids together?
Peptide bonds/amide links
What chemical groups are in the amino acid structure?
Carboxylic group (COOH) Amino group (NH2)
Draw a basic amino acid structure
What is the ionised form of an amino acid also known as?
The disociated form
When do amino acids become ionised?
If the pH of solution is neutral any amino acids in solution will be ionised
How do amino acids develop an ionised form?
The amino acid will either loose/gain protons to the solution which causes the compound to have a charge
What are zwitterions?
Are neutral molecules with positive and negative chrages
What is an easy way to identify if an amino acid is in the non-polar/hydorphobic group?
It is a hydrocarbon
What can a zwitterion act as?
A base (accepting H+ ions) An acid (donating H+ ions)
What is the charge of zwitterions dependant on?
The pH of the solution it is in
What is an R-group?
A collective term for a polymer/a chemical chain
What do R-groups do to amino acids?
Give them their unique chemical properties such as charge and solubility
What are the 4 classifications of R groups?
Acidic (Negatively charged) Basic (Positively charged) Uncharged polar Non-polar
What is the solubility of the 4 classifications of R groups?
Hydrophilic: Acidic (Negatively charged) Basic (Positively charged) Uncharged Polar Hydrophobic: Non-polar
How many acidic amino acids are there?
2
What chemical group do acid amino acids have?
Carboxyl groups (They have more than one)
Give 2 examples of acidic amino acids
Aspartic Acid (Asp, D) Glutamic Acid (Glu, E)
How many basic amino acids are there?
3
What chemical group do basic amino acids have?
NH3+ (Once they have reacted with the neutral solutions)
Give two examples of basic amino acids
Lysine (Lys, K) Arginine (Arg, R)
How many uncharged polar amino acids are there?
5 and they are all hydrophilic
What chemical group do uncharged polar amino acids have?
They all have different functional groups but most contain at least on -OH group
Give two examples of uncharged polar amino acids
Serine (Ser, S) Asparagine (Asn, N)
What is the meaning of hydrophilic compounds?
Compounds which are water loving ie. are soluble in water
What is the meaning of hydrophobic coumpounds?
Compounds which are water hating i.e. they are insoluble in water
How many amino acids are non-polar?
10
Give three examples of non-polar amino acids
Glycine (Gly, G) Alanine (Ala, A) Cysteine (Cys, C)
What are amino acids and what do they form when they are linked together?
Monomers which are linked to make a polypeptide
What chemical reaction causes the joining of amino acids?
Condensation reaction (Dehydration reaction)
Explain the process of how amino acids are joined together
The first amino acid looses an -OH group and the second amino acid looses a H+ group. These groups combine to create water. The two amino acids then bind creating an amide link (peptide bone)
Draw an amide link
(INSERT IMAGE)
What is the plasma membrane made up of?
Fluid mosaic bilayer which consists of phospholipids and proteins
What does amphipathic mean?
When a compound has a hydrophilic and hydrophobic side
Explain why the plasma membrane is amphipathic?
As it has a hydrophilic head group which align to the extracellular space or cytoplasm and the hydrophobic tail points inwards (similar to washing detergent)
What is the term used to describe a protein which is within the membrane?
Integral
What is the term used to describe a protein which is attached to the surface of the membrane?
Peripheral
What determiines where a protein is positioned in the membrane?
The R groups
Where are hydrophilic proteins positioned in the cell membrane?
In the peripheral part of the membrane (Outside)
Where are hydrophobic proteins positioned in the cell membrane?
In the integral part of the membrane (Inside)
What does the plasma membrane consist of?
Mainly fluid mosaic bilayer of phospholipids and protein
What is amphipathic nature?
(of a molecule, especially a protein) having both hydrophilic and hydrophobic parts
Where are the hydrophilic head groups aligned in the plasma membrane?
The extracellular space or the cytoplasm
Where do the hydrophobic tails point in the plasma membrane?
They point inwards
