Biology Unit 4

Marisa Orlow
Mind Map by Marisa Orlow, updated more than 1 year ago
Marisa Orlow
Created by Marisa Orlow almost 5 years ago


Mind Map on Biology Unit 4, created by Marisa Orlow on 04/08/2015.

Resource summary

Biology Unit 4
1 Neuron Communication: Action Potentials
1.1 Neurons generate action potentials: rapid changes
1.1.1 What happens to the resting potential when Na+ channels open? Depolarization! The internal charge becomes more positive
1.1.2 What happens to the resting potential when K+ channels open? Hyperpolarization The internal charge becomes more negative.
1.1.3 Pharmacology of Neurotoxins Dendrotoxin (Black mamba): - K+ channel blocker. Homobatrachotoxin in Central American poison arrow/dart frogs. Known to act on voltage-gated sodium channels Aposematic Warning Brightly colored (toxins)
1.2 At rest it is negative on inside compared to outside
1.2.1 For an action potential to occur, the cell membrane must reach a threshold potential At threshold, more voltage-gated Na+ channels open, allowing Na+ to diffuse rapidly into the cell: DEPOLARIZATION At the peak of the action potential, Na+ voltage- gated channels begin to close, and K+ voltage-gated channels open in response to the positive membrane potential. This returns the membrane toward resting potential: REPOLARIZATION The K+ voltage-gated channels remain open slightly longer than required, and the membrane potential goes below resting. This results in: HYPERPOLARIZATION
2 Muscles
2.1 Properties of Muscle Tissue
2.1.1 Contractility
2.1.2 Excitability
2.1.3 Extensibility
2.1.4 Elasticity
2.1.5 3 Muscle Types Skeletal, Cardiac, Smooth Striated v Non striated (smooth) Voluntary v Involunatry Uni- v Multinucleate
2.2 Muscles contract/work against resistance
2.2.1 Origin - not moving
2.2.2 Insertion- moving
2.3 Motor Units
2.3.1 neuron and muscle cell it excites
2.3.2 we want smaller motor units!
2.3.3 Polio attacks motor unit of spine
2.3.4 Myograph fused tetanus- smooth steady contraction of a muscle Warming up and muscle strength Treppe Stair step effect - need to warm up muscles- generate more tension release of calcium - buildup!
2.4 Exercise and Muscle Contration
2.4.1 Isometric Tension but no load movement
2.4.2 Isotonic Concentric: muscle shortens Eccentric: muscle lengthens
2.5 Energy Sources (all working at once)
2.5.1 direct phosphorylation Anaerobic Pathway Glycolosis- 60 seconds Aerobic pathway Hours oxygen required creatine used to make atp- not a really source 15 seconds
2.6 Skeletal Muscle Fiber Tissue
2.6.1 genetically determined Fast twitch (sprinting muscles) tire quickly Fast twitch Type II A (combo)
2.6.2 slow twitch- how fast myosin heads contract- dark, myoglobin (oxygen carrying)
2.7 Muscle Homeostasis
2.7.1 Atrophy- muscles shrink cast, stomach wraps
2.7.2 Hypertophy HUGE MUSCLES
2.8 Muscle Malfunctions
2.8.1 Fatigue Depletion of ATP Insufficent O2 or glycogen Lactic Acid and ADP buildup Insufficent ACh from motor neurons Decline of Calcium Central Fatigue
2.8.2 Spasms Involuntary twitching Chemical or pschological cramps and tics Charley Horse - leg cramps
2.8.3 Rigor Mortis 3-4 hrs post death 12 hr - max stifness dissipates at 48-60 hours
3 Chemicals
3.1 ATP, Calcium, Na, K, ADP
4 Role of Calcium
4.1 acetylcholine
5 Sensory Mechanisms
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