Topic 2: Genes And Health Flashcards
(29 cards)
In chronological order what vessels does oxygen travel through before diffusion?
Trachea, branchea, bronchioles, alveoli
State Facks law
Rate of gas exchange =
surface area x concentration gradient
_______________________________
thickness of surface
What is the structure of a alveoli?
A collection of balls with large surface area and high blood supply from capillaries maintaining a high concentration gradient. as well as one cell thick walls. Providing maximum rate of diffusion
What two types of cells are found in lung tissue, and what are their functions?
Goblet cells: produce mucus to trap foreign bodies
Ciliated cells: epithelial cells which have rhythmic, wave-like beating cilia attached to the top of them. These hair like structure waft mucus out of the lungs
What does an amino acid consist of? (on a molecular level)
Carboxylic group:
Two hydrogen atoms connected to a nitrogen atom which connects to the left of the central carbon
R group:
Variable group connected to the top of the central carbon
Amine group:
One oxygen atom double bonded to a carbon atom, an OH is also bonded to this carbon atom. The carbon atom is bonded to the right of the central carbon atom.
A hydrogen atom is also connected to the bottom of the central carbon
What determines the R group on an amino acid?
It varies dependant on what protein the amino acid codes for during the translation process
How do two amino acids join? State the reaction and what type of bond is formed
Condensation reaction as water is released, forming a peptide bond between the Carbon atom of the amine group and the Nitrogen atom of the carboxylic group. the bottom H of the carboxylic group and the OH of the amine group are removed as water.
This can be reversed by hydrolysis.
What is the primary structure of a protein?
The sequence of amino acids on a Polypeptide chain
What is a dipeptide and a polypeptide?
A dipeptide is when two amino acids join in a condensation reaction and for a peptide bond. If this process is repeated for and more bonds are made it forms a Polypeptide chain.
What is the secondary structure of a protein?
The chain of amino acids may twist to for a alpha helix shape (like an extended spring) hydrogen bonds between C=O of the carboxylic acid and the -NH of the amine group stabilise the structure.
Several chains may link together with hydrogen bonds holding the parallel chains in arrangement called beta pleated sheets
Both structure can be found in one protein molecule
What is the tertiary and quaternary structure of a protein?
Specific 3D structure of a molecule.
• Ionic bonds between ironised R groups
• Disulphides bonds between R groups containing SH groups
• Hydrophobic interactions of side chains
For quaternary structure, similar bonds form but between different polypeptide chains
What causes a molecule to be hydro-philic/phobic?
Hydrophilic if polar
Hydrophobic if non polar
What are globular proteins? (Provide examples)
Polypeptide chain may be folded into spherical shapes, they are soluble due to the hydrophilic side chains. All enzymes are globular proteins for example haemoglobin, and myoglobin.
What happens when a polypeptide chain is denatured?
The protein structure will not for correctly and not be able to bind to the precise binding site causing the final protein not to function correctly if at all
What is a fibrous protein? (Provide examples)
Do not fold I into a ball shape, remain long chains, several chains can be cross linked for additional strength, they are insoluble. For example keratin in hair and skin, and collagen in the skin, tendons bones and blood vessel walls.
What is the structure of a phospholipid bilayer?
A double layer consisting of phospholipids lined together. The hydrophilic head (negatively charged phosphate group) is on the outer pert of the molecule, connected to two hydrophobic fatty acid chains
State three prices of evidence which support the fluid mosaic model of a membrane
- Phospholipids heads are hydrophilic and the model surrounds them with watery cytoplasm
- Some amino acids are hydrophilic this model allows them motto be in contact with water
- Electron micrographs show the more electron dense heads and the less dense tails
How does diffusion work?
Molecules can move across a permeable membrane if there is a difference concentration gradient by passive transport
Define osmosis and how it is different to diffusion
Osmosis is the movement of water molecules down a concentration gradient. It is different from diffusion as it only applies to water molecules and can go through semi permeable membranes, it is also a passive process
If a phospholipid has more unsaturated fatty acids in the membrane what does this mean? What can reverse this effect?
The ‘kinks’ in the unsaturated hydrocarbon tails prevent them from packing closely making the membrane more fluid.
Cholesterol prevents movement of phospholipids making the membrane less fluid
What is facilitated diffusion?
Hydrophilic molecules and ions which are larger than CO2 cannot diffuse, instead they use channel proteins to defuse through, this is facilitated diffusion. Gated channels need a signal (voltage, hormone) to allow for diffusion.
Carrier proteins can also be used which have a specific binding site for specific molecules
This is still a passive transport as it only occurs down a concern traction gradient
what is active transport?
Active transport can be used to move substances across the membrane against the concentration gradient, this process requires ATP. This process is what people with CF lack in their CFTR protein.
A carrier protein has a specific binding site, when the correct molecule binds in this site tho carrier protein encloses around it and releases it into the cell
What is exocytosis?
Vesicles carries substances to the cell membrane then fuses with the cell membrane releasing the substances
What is endocytosis?
This is where a membrane engulfs a substance and it is then a vesicle inside the cells cytoplasm
This process requires input energy in the for of ATP
