Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

AL Biology > 15) Control & Co-ordination > Flashcards

15) Control & Co-ordination Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

list 5 key ideas about hormones

A
  • proteins or steroids
  • released by endocrine glands
  • directly into the blood
  • act as messengers
  • affect target organs/ cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are 3 peptide hormones

A
  • ADH
  • insulin
  • glucagon

(cell signalling molecules)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how do peptide hormones pass through the membrane?

A
  • cannot pass through directly
  • since they are hydrophilic
  • so they bind to receptors in the plasma membrane of a target cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

5 differences between the endocrine system and the nervous system

A

Endocrine system
- communication = HORMONE
- nature of communication= chemical
- mode of transmission = blood
- response destination = target organs/cells
- transmission & response speed = slower
- effects = widespread
- duration = longlasting/permanent

Nervous system
- communication = action potential/impulse
- nature of communication= electrical (& chemical)
- mode of transmission = neurone
- response destination = muscle/gland
- transmission & response speed = faster
- effects = specific
- duration = short lived/temporary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

describe the structure of a motor neurone

A
  • cell body at end of neurone
  • cell body in CNS
  • long axon
  • dendrites attached to cell body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

describe the structure of a sensory neurone

A
  • cell body in middle of neurone
  • nucleus in cell body
  • short axon
  • dendrites attached to dendron
  • long dendron
  • many mitochondria in cell body
  • many RER/ribosomes in cell body
  • synaptic knobs
  • myelin sheath/ schwann cells
  • nodes of Ranvier
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how does the myelin sheath increase the speed of conduction of nerve impulses

A
  • it insulates axon
  • action potential only at nodes of Ranvier
  • local circuits set up between nodes
  • action potential jumps from node to node
  • saltatory conduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is a transducer

A

convert energy in one form (light/heat) into electrical energy within a sensory neurone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

role of chomoreceptor cell in detecting stimuli and stimulating action potential

A
  • chemicals act as a stimulus
  • specificity of chomoreceptors
  • Na+ diffuse into cell via microvilli
  • membrane depolarised
  • receptor potential
  • stimulates opening of Ca+ channels
  • Ca+ enter the cell
  • vesicles with neurotransmitter move/fuse
  • neurotransmitter released by exocytosis
  • neurotransmitter stimulates action potential
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is a resting potential set up and maintained in a myelinated neurone [9]

A
  • Na+ moves out of the cell and K+ moves into the cell. by active transport.
  • 3 Na+ for every 2 K+.
  • sodium potassium pump.
  • against concentration gradient
  • K+ diffuses out of cell & Na+ diffuses into.
  • by facilitated diffusion.
  • membrane more permeable to K+ so more K+ goes out than Na+ in.
  • inside of the cell is more negative than the outside
  • membrane polarised
  • resting potential = -70mV
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

describe the transmission of an action potential in a myelinated neurone [9]

A
  • stimulus occurs
  • Na+ channels open
  • Na+ enters the cell
  • causes depolarisation as inside of the cell becomes less negative
  • Na+ channels close
  • K+ channels open
  • K+ moves out of the cell
  • repolarisation = inside becomes negative
  • local circuits
  • myelin sheath insulate axon
  • action potential ONLY at nodes of Ranvier
  • saltatory conduction (action potential jumps from node to node)
  • hyperpolarisation
  • back to resting potential
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the importance of the refractory period

A
  • ensures action potentials are discrete events, stopping them from merging into one another
  • ensures the charge of the membrane potential is generated ahead rather than behind the original action depolarisation
  • so impulse can only travel in one direction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is a synapse

A

where two neurones meet but do not actually touch - a tiny gap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

synaptic transmission

A
  • Ca2+ channels open
  • Ca2+ enters presynaptic knob
    -vesicles contain neurotransmitter ACh
  • vesicles fuse with presynaptic membrane
  • ACh released by exocytosis
  • ACh diffuses across the cleft
  • binds to receptors on post-synaptic membrane
  • Na+ channels open
  • Na+ enters post-synaptic neurone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the role of acetylcholinesterase [2]

A
  • breaks down neurotransmitter ACh
  • recycles ACh
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

why are there tight junctions between chemoreceptor cells

A

so theres no movement of substances between the chemoreceptor cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

breakdown the structure of a muscle

A
  • muscle
  • muscle fibres
  • myofibrils
  • myofilaments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

2 types of myofilaments

A

actin - thin
myosin - thick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are myofilaments

A

repeating contracting units in a sarcomere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

when the muscle contracts, what happens

A

I band = shorter
A band = same

21
Q

when the muscle is relaxed what happens

A
  • sarcomere is longer
  • H band longer/wider
  • light area on each side of Z line longer
22
Q

one sarcomere = between 2 Z lines

A

one sarcomere = between 2 Z lines

23
Q

neuromuscular junction

A
24
Q

what is the importance of the Schwann cell in transmission of nerve impulses

A
  • myelin sheath
  • insulates axon
  • increases speed of impulse
  • saltatory conduction
25
Q

why is mitochondria needed in neuromuscular junction?

A
  • produces ATP
  • for recycling ACh
  • for movement of vesicles
  • for contraction of sarcomeres
  • for sodium potassium pumps/ active transport
26
Q

events occuring during muscle contraction

A
  • sarcolemma depolarised
  • transverse tubules depolarised
  • Ca2+ ions diffuse out of sarcoplasmic reticulum
  • Ca2+ ions bind to troponin
  • troponin changes shape
  • tropomyosin moves
  • binding sites on actin exposed
  • myosin heads bind to actin
  • myosin heads tilt & pull actin so sarcomere shortens
  • myosin head binds to ATP to allow detachment
27
Q

why do venus flytraps trap flies

A
  • not enough nitrate in soil
  • poor mineral content of soil
28
Q

response of venus flytraps to touch

A
  • mechanical energy converted to electrical
  • sensory haircells is receptor
  • cell membrane depolarises
  • if atleast 2 hairs touched within 35 secs, action potential occurs
  • action potential spreads over leaf
  • H+ pumped out of the cell into cell walls
  • cell wall loosens & cross-links broken
  • calcium pectate dissolves
  • Ca2+ enter cells
  • water enters by osmosis
  • cells become turgid
  • change from convex to concave
  • trap shuts quickly in <1secs
  • acid growth hypothesis
29
Q

role of Auxin in cell elongation

A

-auxin binds to receptor in cell surface membrane
- auxin increases proton pump activity
- more protons (H+) enter cell wall
- cell wall becomes acidic/less pH
- expansins activated
- expansins break bonds between cellulose microfibrils
- K+ enters cell
- w.p of cell decreases
- water enters by osmosis
- turgor pressure so walls stretch
- acid growth hypothesis

30
Q

why do aleurone layers of barley seeds need to produce amylase during germination

A
  • amylase enters endosperm
  • amylase hydrolyses starch to form maltose
  • maltose converted to glucose
  • glucose transported to embryo = providing energy for growth/ATP production
31
Q

explain how endorphins may act to reduce pain

A
  • endorphins bind to (endorphin) receptors
  • stop calcium ions / Ca2+, entering presynaptic knob
  • no / fewer vesicles fuse with, (presynaptic) membrane
  • no / less ACh, released
  • no / less, binding of ACh to postsynaptic receptors
  • no / less, depolarisation of postsynaptic, neurone / membrane
  • no / fewer, action potentials / impulses, to, pain centre / brain
32
Q

When a mammal dies, aerobic respiration stops. The striated muscles contract and remain
contracted for a few hours after death. Why?

A
  • no ATP produced
  • so no breaking of cross bridges / myosin head not released
33
Q

location of gibberellin synthesis in a barley seed during germination

A

embryo

34
Q

why does germination increase as water potential increases

A
  • low / negative, water potential decreases water uptake in seed
  • water needed to activate embryo / produce gibberellin
  • water needed for hydrolysis (reactions)
  • starch to maltose / maltose to glucose
  • water needed as a medium for reactions
35
Q

what enzyme does gibberellin stimulate and where

A
  • amylase / maltase/ protease
  • aleurone layer
36
Q

sequence of events that lead to poduction amylase during germination

A
  • embryo absorbs water
  • (stimulates) embryo to produce gibberellin
  • gibberellin moves to aleurone layer
  • gene coding for amylase, expressed
  • translation of mRNA (to produce amylase)
37
Q

where are starch reserves in a barley seed

A

endosperm

38
Q

diff in function between motor and sensory neurones

A
  • motor neurones - transmits impulses from CNS to effector
  • sensory neurones - transmits impulses from receptors to CNS
39
Q

what is the function of microvilli in chemoreceptors

A
  • increase surface area
  • for more Na+ channels/ more Na+ can enter
40
Q

why is the speed of transmission faster in a myelinated neurone

A
  • Na+ channels ONLY at nodes of Ranvier (in non-myelinated its all along the neurone)
  • depolarisation ONLY occurs at nodes
  • long local circuits
  • saltatory conduction
41
Q

explain what is happening in the striated muscle fibre during
the latent phase.

A
  • transverse / T- , tubules depolarised
  • Ca2+ diffuse out of sarcoplasmic reticulum
  • Ca2+ bind to troponin
  • tropomyosin moves from binding sites
  • for myosin on actin
  • cross-bridges form / myosin (head) binds to actin
42
Q

why preventing the free movement of mitochondria within the cytoplasm of the axon affects the transmission of action potentials along the axon
membrane

A
  • no ATP for sodium potassium pump/active transport of Na+ and K+
  • reduces/prevents resting potential
  • reduces transmission of action potential
43
Q

Explain how the speed of transmission of nerve impulses in people with GAN can affect
walking

A
  • takes longer for impulses to reach impulses
    -fewer/slower muscle contractions
  • slower reflexes
  • walks slower/trips
44
Q

Suggest reasons why a reduction in temperature can decrease the efficiency of contraction of striated muscle cells.

A
  • respiration rate/ATP decreases
  • reduces activity of enzymes
  • reduces movement of Ca2+/ACH/Na+
  • no acetylcholine broken down
  • acetylcholinesterase inactive
  • no Ca2+ bind to troponin
  • no cross bridges formed
  • no detachment of myosin heads
  • no cross bridges broken
45
Q

similarities in structure between a neuromuscular junction and a cholinergic
synapse

A
  • acetylcholine from vesicles
  • many mitochondria
  • have presynaptic and postsynaptic membranes
  • (synaptic) cleft / gap
  • have receptor(s) (for ACh / neurotransmitter) ;
  • presynaptic Ca2+ channels
46
Q

Suggest why calcium phosphate formation in the sarcoplasmic reticulum may result in
fewer power strokes occurring in sarcomeres

A
  • few(er) Ca2+ ions, leave sarcoplasmic reticulum / enter sarcoplasm
  • few(er) Ca2+ ions bind to troponin
  • few(er) troponin molecules change shape
  • few(er) tropomyosin molecules move
  • few(er) myosin-binding sites, uncovered / exposed
  • few(er), actin-myosin cross bridges form / myosin (heads) bind to actin
47
Q

Suggest how developing muscle cells that express stress genes will differ in structure from
normal muscle cells

A
  • less actin
  • less myosin
  • less troponin
  • less tropomyosin
  • fewer / smaller sarcomeres / myofibrils
48
Q

what does acetylcholinesterase do

A
  • binds to ACh receptors
  • so that Na+ channels open
  • Na+ enters
  • sarcolemma depolarised
49
Q

role of synapses

A
  • one way transmission of impulses
  • communication between many neurones

AL Biology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions