Lecture 1 Flashcards
What are the 4 unifying themes/principles in physiological design?
- physiological processes obey laws of physics and chemistry
- physiological processes are usually regulated
- physiological phenotype is a product of the genotype and environment
- genotype is the product of evolution
What is the giraffe example for physical and chemical laws of physiological processes?
The giraffe has tight skin and thin legs to help pump blood back up to trunk, because of how tall it is, its harder to pump blood upwards.
What are the two ways that animals deal with a constantly changing environment?
External regulation
Endogenous (self imposed) regulation
What kind of controls are used in feedback loops to control homeostasis?
Antagonistic controls
Give an example of antagonistic controls ina feedback loop for elevated body temperature
The body is exposed to heat, body temperature rises, the body decreases heat producing pathways, and increases heat dissapation pathways until homeostasis is achieved
What are the two strategies for coping with changing conditions?
Conformers and regulators
What is a conformer?
Allow internal conditions to change with external conditions (example: ectotherms)
What is a regulator?
maintain relatively constant internal conditions regardless of external conditions- requires metabolic energy
What is genotype
genetic makeup
what is phenotype
morphology, physiology, behaviour
what is phenotypic plasticity?
single genotype generates more than one phenotype depending on environment
What are the main components if a membrane?
Lipids, proteins and carbohydrates
What 3 kinds if lipids are in a membrane
phospholipids, glycolipids and sterols
What 2 kinds of proteins are in a membrane?
integral and peripheral
What two carbohydrates are in a membrane?
glycolipids and glycoproteins
True or false: The head of a phospholipid is hydrophobic
False
True or false: The tails of a phospholipid are nonpolar and hydrophobic
True
Do double bonds in the fatty acid tails make the membrane more or less fluid?
Having more double bonds makes it more fluid
Describe the function of a channel protein
Uses passive movement, it is a channel thats always open
Describe the function of a transporter protein
Uses either active transport if it uses energy or facilitated diffusion if not. It opens on one end, grabs molecule, transforms and then lets it out on the other end
Describe the function of an enzyme protein
catalyzes a chemical reaction
Describe the function if a receptor protein
Binds to specific molecules and initiates a change in membrane permeability or cell metabolism
What is the function of a structural protein
attaches to other molecules or to the cell membrane to act as an anchor
what molecules have an easier time getting through membranes?
Small uncharged molecules and lipid soluble substances
What molecules need help to pass through membranes?
water soluble substances and ions
In passive diffusion, what kind of molecule must it be?
Lipid soluble
What are 4 types of channels that use facilitated diffusion?
Voltage gated channel
Stretch gated channel
Phosphorylation gated channel
Ligand gated channel
Is there an electrical or chemical gradient, or both? Explain
There is both because sometimes molecules will want to move to reach equilibrium, but charged ions also want to move
Name the 4 receptor types talked about i lecture
Ligand gated channel
G-protein coupled
Enzyme/enzyme linked
Intracellular
Describe a ligand gated channel receptor
Acts as a receptor and channel, needs a ligand to open the gate
Describe the process if a g protein coupled receptor
Ligand binds to g protein coupled receptor, activates g protein, intracellular effects or more commonly interacts with another membrane protein
Describe the process of enzyme linked receptors
Ligand binds, activates catalytic site on the same molecule, this causes production of the second messenger cyclic GMP
Describe the process of intracellular receptor
The ligand is a hormone so it can go through the membrane, it binds to receptor, activates it, in the nucleus it binds to DNA to cause change in gene expression
