Unit 6: Systems within Organisms Flashcards
what are the 2 types of movement
movement within cells
locomotion (moving from one place to another)
motile vs sessile
motile = organisms that can do locomotion
sessile = organisms that remain in one location
what is the sliding filament model of muscle contraction
striated muscle fibres has the stripes. this is caused by something called a sarcomere
see B3.3.2 for structure
when contract, myosin pulls the actin filaments + z-line closer
see iPad for the model
what is titin
titin = connects myosin to the z-line
- biggest polypeptide
it is very elastic (has spring motion)
prevents z-lines from getting too far apart
makes muscle contractions stronger
when muscle is relaxed, titin is stretched
contract = spring recoil
role of antagonistic muscles in muscle relaxation
muscles that accomplish opposite movements
(i.e. bicep and tricep)
when one contracts, the other stretches, stretching the titin, which can recoil to make contraction stronger
structure and function of motor units in skeletal muscle
neuromuscular junction: where a motor neuron meets a muscle fiber
acetylcholine = transfers messages from neurons to muscles
motor unit = motor neuron + all of the muscle fibers it connects to (B3.3.4 iPad)
–> for coordinated contraction
what is the role of skeletons
muscles provide pulling force, skeletons provide ANCHORAGE points
- levers
Fulcrum = pivot point of a lever
movement at a synovial joint
see B3.3.6 on iPAD
range of motion in a joint
- hinge joint = can only flex or extend
- ball and socket joint = capable of rotation, adduction/abduction (side to side), protraction/retraction (up and down)
can be measured with a goniometer
internal and external intercostal muscles
inhaling:
ribcage up and out
external contract
exhaling:
ribcage in and down
internal contract
reasons for locomotion
finding food
finding a mate
escaping predators
migration
adaptations for swimming in marine mammals
- streamlined body (teardrop shape, no hair to reduce friction)
- airways (blowhole, mouth not connected to lungs)
- locomotion (fins, flippers, tails, blubber for buoyancy)
gas exchange in animals
universal function in organisms
properties of gas-exchange surfaces
- thin
- permeable to gases
- large surface area to volume ratio
- moist
maintenance of conc. gradients at exchange surfaces in animals
higher gradient = faster diffusion
needs constant blood flow
ventilation = moving air into and out of the lungs through dense networks of blood vessels
fish = move fresh water through gills
adaptations of mammalian lungs
diaphragm
intercostal muscles
abdominal muscles
ribs
ventilation of the lungs
inhaling:
1. diaphragm and external IM contract
2. abdominal and interior IM relax
3. inc. chest cavity volume
4. pressure decreases
5. air is forced into our lungs
exhaling:
1. diaphragm and external IM relax
2. abdominal and interior IM contract
3. dec. chest cavity volume
4. pressure increases
5. air is forced out of our lungs
measurements of lung volumes
ventilation rate: number of inhalations/exhalations per minute
tidal volume: volume of air inhaled/exhaled in each breath
vital capacity: maximum amount of air the lungs can hold
inspiratory reserve vole: amount of air a person can inhale after a normal breath
expiratory reserve volume: amount of air a person can exhale after a normal breath
can use a spirometer or a bell jar to measure lung volumes
adaptations for gas exchange in leaves
stomata = openings for gas exchange and water loss
distributions of tissues in a leaf
see b3.1.8
consequences of gas exchange in a leaf
transpiration = loss of water vapour from the leaves
higher temp = more transpiration
higher humidity = less transpiration
guard cells can open and close stomata to control water loss
can measure transpiration using a potometer
how to measure stomatal density
stomata/cm^2
what is cooperative/allosteric binding of O2/CO2 to haemoglobin?
haemoglobin can transport 4 oxygen molecules
when oxygen binds to one of the haem groups, it causes a conformational change, increasing its affinity for oxygen
= cooperative binding
this is reversible
haemoglobin w/ 3 O molecules will have the greatest affinity for oxygen. w/ 4 O molecules = no affinity. w/ 0 O molecules = least affinity (besides 0)
allosteric binding
CO2 will bind to the polypeptide regions of the molecule, known as the allosteric site of the polypeptide
binding of CO2 = release of O molecules (BOHR SHIFT)
adaptations of capillaries for exchange of materials between blood
capillaries = site of diffusion into and out of the blood
–> have a large surface area
tissues that need lots of oxygen or nutrients have a high-density capillary network
-pores = to increase permeability
- fluid that comes out of the capillaries = tissue fluid (water, oxygen, glucose, ions)
—> tissue fluid leaves the capillaries and flower between tissues
—> materials diffuse into tissues, waste diffuses into tissue fluid
—> fluid returns to capillaries