Genes and Health Flashcards
Explain the anatomical adaptations in organisms with respiratory systems that maximise gas exchange
High surface area on gas exchange surfaces increases the rate of diffusion, obtained with many alveoli in the lungs.
Short diffusion pathway so gas can travel from one medium to another quickly, obtained through having thin walls between alveoli and capillaries.
High concentration gradient to increase rate of diffusion, obtained via breathing fresh air and constant flow of deoxygenated blood.
What is the formula for ficks law.
rate of diffusion = surface area x difference in concentration / thickness of gas exchange surface
Explain how an Increased thickness of gas exchange surface due to thicker mucus would affect the rate of gas exchange
it would decrease it as in ficks law a higher thickness would divide the rate of diffusion.
Explain how a Reduction in the concentration gradient between the alveolar space and capillaries would affect the rate of gas exchange
It would decrease the rate of gas exchange as in the ficks law equation the concentration gradient is a multiplier.
Explain how Damage to alveoli resulting in a reduction in their number would affect the rate of gas exchange
It would decrease the rate of gas exchange as in the ficks law equation surface area is a multiplier.
Explain the role of goblet cells in the respiratory system
Produces mucus
Explain the role of ciliated epithelial cells in the respiratory system
used to transport mucus to remove pathogens from the lungs.
Describe how amino acids react together to form a polypeptide
Condensation reaction where amine group joins to carboxyl group to form a peptide bond.
Give a definition of the primary structure of a protein
The number of amino acids and the order they are arranged in a polypeptide chain
Describe how the secondary structure of a protein forms from the primary structure
The secondary structure of a protein is created by hydrogen bonds in the polypeptide chain causing the chain to form alpha helix shapes or beta pleat shapes.
Describe how the tertiary structure of a protein forms from the secondary structure
Tertiary structure is formed by R group bonds (hydrogen bonds, ionic bonds etc.) between alpha helixes and beta pleats causing them to fold over one another into more complex shapes
Explain how the primary structure of a protein determines the functional shape of the protein
The primary structure of a protein (the sequence of amino acids in the chain) determines how the protein will fold. The sequence of variable groups and how they interact with each other through hydrogen and sulfide bonds will determine the secondary structure (of alpha helices and beta pleated sheets), which will help determine the tertiary structure (the overall shape of that individual protein), and thus its function.
Describe the structure of a globular protein
Polypeptide chain that has folded into a spherical shape. Polar R groups face outwards.
Explain how the structure of a globular protein determines its function and properties
Globular proteins have polar R groups on the outside of the spherical molecule, which means it will have hydrophilic properties which means it is soluble in water.
Describe the structure of a fibrous protein (incl. specific reference to collagen)
Fibrous proteins do not have a tertiary structure, and instead wrap around each other to form long, thin structures where polar R groups face inwards, such as collagen which is made up of 3 alpha helix polypeptide chains wound together in a helical structure
Explain how the structure of a fibrous protein determines its function and properties
Fibrous protein has no outward facing polar R groups so it is insoluble in water, and due to their closely linked polypeptide chains, they have a high tensile strength.
Describe the structure of a phospholipid
Glycerol base with 2 fatty acid chains and a phosphate group. Has a polar side (hydrophilic) and a non polar side (hydrophobic).
Describe the structure and properties of phospholipids
phospholipids are composed of a phosphate group, two alcohols, and one or two fatty acids. On one end of the molecule are the phosphate group and one alcohol; this end is polar, i.e., has an electric charge, and is attracted to water (hydrophilic).
Explain why phospholipids form a bilayer in cell membranes
Because their fatty acid tails are poorly soluble in water, phospholipids spontaneously form bilayers in aqueous solutions, with the hydrophobic tails buried in the interior of the membrane and the polar head groups exposed on both sides, in contact with water
List the components of cell membranes and give a function for each
Proteins:
play a role in many other functions, such as cell signaling, cell recognition, and enzyme activity.
Phospholipids:
Interactions between polar heads and non polar tails create a bilayer which forms the basis of a plasma membrane
Carbohydrates:
Carbohydrates combine with protein molecules to form a glycoprotein,
Glycoproteins play a role in the interactions between cells, including cell adhesion, the process by which cells attach to each other.
Explain why the cell membrane is called a fluid mosaic
Because it is made up of many different components which can move freely around each-other, giving it the appearance of a mosaic that moves like a fluid.
Explain how the level of cholesterol affects membrane fluidity
higher cholesterol levels increase membrane fluidity by increasing distances between phospholipids allowing them to slide around one another
Explain how saturated and unsaturated phospholipid tails affects membrane fluidity
Saturated tails will decrease membrane fluidity as the tails will pack closely together preventing movement, whereas unsaturated tails will increase membrane fluidity as they do not pack closely together and so can move freely around eachother
Give reasons why the three-layer protein lipid sandwich theory of membrane structure was rejected as a model
It did not account for the permeability of certain substances,
as it did not explain the transport mechanism to allow certain substances across the membrane.
Give a definition of osmosis
The movement of water from an area of low solute concentration to an area of high solute concentration, through a partially permeable membrane.
Under what conditions would water move into a cell via osmosis?
When there is a higher concentration of water outside the cell than inside.
Under what conditions would water move out of a cell via osmosis?
When there is a higher concentration of water inside the cell than outside.
Explain why plant cells store glucose in the form of amylose/amylopectin and animal cells store glucose in the form of glycogen
Plants store glucose as starch because it can be broken down quickly and it is insoluble which means it does not disrupt osmotic balance,
Animals store glucose as glycogen as it can be broken down quickly and it is insoluble which means it does not disrupt osmotic balance
Explain how and why the hydrolysis of amylopectin/glycogen stored in a cell would impact the movement of water via osmosis
It would impact the movement of water via osmosis as water would be used up in a hydrolysis reaction, causing the concentration of water in that area to decrease, which would cause water to move towards the area of lower water concentration.
Explain the role of the CFTR protein
Acts as a medium to allow chloride ions to transport across a cell membrane
Explain how a faulty CFTR protein results in thicker, stickier mucus in CF sufferers
Faulty CFTR - Always open
- Cl- Ions transport from mucus into cell
- Travel across cell membrane into tissue fluid via diffusion
- Na+ ions travel along electrochemical gradient from mucus to tissue fluid between cells
- Water potential within the cell is higher than tissue fluid, water travels via osmosis from cell to tissue fluid,
Water potential within mucus higher than cell, water gtravels via osmosis from mucus to cell, causing it to be thicker and stickier and more viscous
Explain the effects of CF on the respiratory system
Cf means no cftr protein in membrane, which means water is constantly removed from mucus which results in thicker stickier mucus. This mucus cannot be moved by cilia cells which means there is a longer diffusion pathway as the mucus builds up a thick layer, which reduces rate of diffusion. Also, dirt and pathogens trapped inside the mucus cannot be moved out of the lungs so pathogens will cause infections inside the lungs.
Explain the effects of CF on the reproductive system, incl. both males and females
female: thick mucus creates a mucus plug in the cervix which can block sperm from reaching the egg during reproduction
Male: thick Mucus gathers inside the vas deferens canal as it cannot be moved by cilia, which means sperm is blocked from reaching the urethra as the sperm canal is blocked.
Explain the effects of CF on the digestive system
Thick mucus is produced in the pancreas, mucus cannot be removed which means it eventually builds up and blocks the pancreatic duct. this means enzymes produced in the pancreas cannot reach the intestines, so food cannot be digested in the intestines and the enzymes will instead cause damage to the pancreas by breaking it down
Describe and explain the effect temperature has on membrane permeability
Higher temperature increases membrane permeability as the phospholipids have more kinetic energy which means they move around eachother more, creating more gaps for small molecules to pass through the membrane.
