Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > Topic 7 > Flashcards

Topic 7 Flashcards

1
Q

What attaches skeletal muscle to bone?

A

Tendons

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

What attaches bone to bone?

A

Ligaments

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

What is skeletal muscle made up of?

A

Muscle fibres

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

What is the cell membrane of muscle fibre cells called?

A

Sarcolemma

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

What is sarcolemma?

A

The cell membrane of muscle fibre cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is sarcoplasm?

A

A muscle cell’s cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are transverse (T) tubules?

A

Infolds of sarcolemma which distribute electrical impulses throughout the sarcoplasm so they reach all parts of the muscle fibre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the sarcoplasmic reticulum?

A

Internal membranes running through the sarcoplasm. Stores and releases calcium ions

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

What is special about the contents of muscle fibre cells?

A

Contain main ATP, are multinucleate (contain many nuclei), contain myofibrils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are myofibrils?

A

Long, cylindrical organelles made up of proteins specialised for contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the structure of a myofibril?

A

Contains thick and thin myofilaments that move past each other in contraction. Made of many repeating units called sarcomeres. Also contains tropomyosin and troponin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are thick myofilaments made of?

A

Myosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are thin myofilaments made of?

A

Actin

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

What is the structure if myosin filaments?

A

Thicker myofilaments. Hinged globular heads that can move back and forth. Myosin heads have a binding site for actin and a binding site for ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the structure of actin filaments?

A

Thinner myofilaments. Have binding sites for myosin heads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the function of tropomyosin and troponin?

A

Tropomyosin blocks actin-myosin binding site in a resting muscle and is held in place by troponin. Troponin changes shape when Ca2+ binds, which moves tropomyosin out of the way

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

How does muscle contraction take place?

A

1) Action potential from motor neurone depolarises the sarcolemma.
2) Depolarisation spreads down T-tubules to the sarcoplasmic reticulum
3) Ca2+ released into sarcoplasm
4) Ca2+ binds to troponin, changing its shape, moving tropomyosin and exposing binding sites
5) Myosin head can bind to actin filament
6) Ca2+ ions also activate ATPase which breaks ATP down and provides energy
7) This energy moves the myosin head, pulling actin filament along
8) ATP also provides energy to break actin-myosin cross bridge so the head detaches
9) Head attaches to a different binding site, repeats cycle
10) Cycle continues as long as Ca2+ is present and bound to troponin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens when muscle excitation stops?

A

Ca2+ leaves troponin binding sites. Moved by active transport back into sarcoplasmic reticulum. Troponin returns to original shape. Tropomyosin again blocks binding sites. Actin filaments slide back to relaxed position.

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

Properties of slow twitch muscle fibres?

A 
Contract slowly
Used for posture
Good for endurance
Work a long time without tiring
Energy released aerobically
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Properties of fast twitch muscle fibres?

A 
Contract quickly
Used for fast movement
Good for short burst of power
Tire quickly
Energy released anaerobically
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the four stages of aerobic respiration?

A

Glycolysis, the link reaction, the Krebs cycle and oxidative phosphorylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Where does Glycolysis occur?

A

Cytoplasm of cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Where does the link reaction occur?

A

Matrix of Mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where does the Krebs cycle occur?

A

Matrix of Mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Where does oxidative phosphorylation occur?
Inner Mitochondrial Membrane
26
What happens in the first stage of aerobic respiration?
Glycolysis: One molecule of glucose is split into two molecules of pyruvate
27
What are the two stages of glycolysis?
Phosphorylation and oxidation. 1) Glucose phosphorylated by 2 molecules of ATP - creates 2 molecules of triose phosphate and 2 ADP 2) Triose phosphate loses hydrogen to form 2 pyruvate. NAD collects hydrogen ions, forming 2 reduced NAD. Process produces 4 ATP but net gain is 2 ATP for glycolysis
28
What happens in the second stage of aerobic respiration?
The link reaction: 1) Pyruvate decarboxylated (carbon removed) - one C removed in form of CO2 2) NAD is reduced by collecting hydrogen from pyruvate. Pyruvate becomes acetate 3) Acetate combined with coenzyme A to form acetyl coenzyme A 4) No ATP produced here
29
How often do the link reaction and Krebs cycle occur per glucose molecule?
Twice
30
What happens in the third stage of aerobic respiration?
The Krebs Cycle: 1) Acetyl CoA combines with oxaloacetate to form citrate. CoA reused in link reaction. 2) 6C citrate converted to 5C molecule be decarboxylation. Also dehydrogenated and reduced NAD produced 3) 5C molecule converted to 4C molecule - decarboxylation and dehydrogenation which produces 1 reduced FAD and 2 reduced NAD 4) ATP produced by direct transfer of phosphate ground from an intermediate compound to ADP. This is called substrate level phosphorylation. Oxaloacetate has been reformed from citrate.
31
Fate of 1 coenzyme A from Krebs?
Reused in link reaction
32
Fate of Oxaloacetate from Krebs?
Regenerated and used in next Krebs cycle
33
Fate of 2 CO2 from Krebs?
Released as waste
34
Fate of 1 ATP from Krebs?
Used for energy
35
Fate of 3 reduced NAD from Krebs?
Goes to oxidative phosphorylation
36
Fate of 1 reduced FAD from Krebs?
Goes to oxidative phosphorylation
37
What happens in the fourth stage of aerobic respiration?
Energy carried by electrons from reduced coenzymes (NAD and FAD) is used to make ATP
38
What are the two processes of oxidative phosphorylation?
1) Hydrogen atoms released by reduced coenzymes as they are oxidised. 2) H atoms split to H+ and e- 3) Electrons move along electron transport chain, losing energy which is used to pump protons from the mitochondrial matrix into the intermembrane space 4) This forms electrochemical gradient of protons, higher in the intermembrane space than matrix 5) Protons move back down gradient into mitochondrial matrix via ATP synthase 6) At the end of the transport chain, protons, electrons and O2 from blood combine to form water. Oxygen is the final electron acceptor.
39
What is the name of the movement of H+ ions across a membrane to produce ATP called?
Chemiosmosis
40
How many ATP can be made from one glucose in aerobic respiration?
32
41
How can you measure rate of respiration?
* Using a respirometer. Measures rate of oxygen uptake. * 2 tubes, syringe, manometer, closed tap, woodlice, beads of same mass as woodlice * Potassium hyrdoxide solution in each tube to absorb CO2 * Syringe use to set manometer fluid to known level * Pressure change moves liquid toward test tube * Distance moved measured and used to calculate O2 vol per minute
42
How does anaerobic respiration work?
Lactate fermentation: * Glucose converted to pyruvate via glycolysis * Reduced NAD from glycolysis transfers hydrogen to pyruvate to form lactate and NAD * NAD reused
43
What is the fate of lactate?
Converted back to pyruvate by cells or glucose by the liver
44
What does myogenic mean?
A muscle that can contract and relax without receiving signals from neurones
45
How is heartbeat regulated?
* SAN sends out regular waves of electrical activity through the atrial walls causing atria to contract simultaneously * Band of collagen is non conducting and prevents electrical signal reaching ventricles directly * Waves reach AVN - there is a slight delay and then the waves are passed on to the bundle of His * Passed down bundle of His * Carried by Purkyne fibres into the muscular walls of the left and right ventricles causing bottom up simultaneous contraction
46
What and where is the SAN?
Sinoatrial node - wall of the right atrium
47
What and where is the AVN?
Atrioventricular node - wall of right atrium
48
What is the bundle of His?
Group of muscle fibres responsible for conducting waves of electrical activity to the Purkyne fibres
49
What are the Purkyne fibres?
The finer muscle fibres in the right and left ventricle walls
50
What is an ECG?
Electrocardiograph
51
What does an ECG do?
Records the electrical activity of the heart
52
What are the components of an ECG trace?
P, Q, R, S and T
53
What causes P wave?
Contraction of atria
54
What is the QRS complex?
Main peak, caused by contraction of ventricles
55
What causes the T wave?
Relaxation of ventricles
56
What is a normal heart rate?
60-100 bpm
57
What is increased heart rate called?
Tachycardia
58
What is tachycardia?
Increased heart rate, sign of heart failure
59
What is fibrillation?
Irregular heart beat
60
What is an irregular heat beat called?
Fibrillation
61
What is the medulla?
Part of the brain controlling breathing rate and heat rate
62
What controls breathing rate?
Part of the brain called the medulla
63
What is the the structure of the medulla?
Has areas called ventilation centres - the inspiratory centre and expiratory centre Also has cardiovascular control centre
64
How does the medulla control breathing rate?
* Inspiratory centre in medulla sends nerve impulses to intercostal and diaphragm muscles making them contract. Increases volume and decreases pressure of lungs, drawing in air * Stretch receptors stimulated which send impulses to medulla, inhibiting the action of the inspiratory centre * Expiratory centre sends nerve impulses causing the diaphragm and intercostal muscles to relax, causing deflation of lungs
65
How is increased breathing rate triggered by exercise?
* Level of CO2 in blood increases, reducing pH * Changes in blood pH detected * Nerve impulses sent to medulla which sends more frequent impulses to diaphragm and intercostal muscles
66
How is blood pH detected?
Chemoreceptors in the medulla, aortic bodies and cartoid bodies
67
What is ventilation rate?
Volume of air breathed in or out in a period of time
68
What does heart rate change in response to?
* Blood pH increases, detected by chemoreceptors | * Pressure changes it accordingly, detected by pressure receptors in aorta wall and carotid sinuses
69
What is cardiac output?
Total volume of blood pumped by a ventricle every minute
70
What is stroke volume?
Volume of blood pumped by one ventricle per contraction
71
What is tidal volume?
The volume of air in each breath
72
What is breathing rate?
Breaths per minute
73
How can tidal volume and breathing rate be measured?
With a spirometer. Person breathes in oxygen from oxygen chamber and breathes back into it. Soda lime in the tube absorbs CO2. Movement of lid of chamber recorded
74
What part of the brain regulates body temperature?
The hypothalamus
75
How do transcription factors help regulate temperature?
Bind to DNA sites near the start of genes and alter rate of transcription. At low temperature a hormone binds to a transcription factor for a protein affecting metabolic rate, increasing rate of transcription for it.
76
Advantages of keyhole surgery?
* Less blood loss * Less scarring * Less pain * Quicker recovery * Easier to return to normal activities * Shorter hospital stays
77
What are examples of performance enhancing drugs?
Anabolic steroids Stimulants Narcotic analgesics
78
What do anabolic steroids do?
Increase strength, speed and stamina by increasing muscle size and allowing athletes to train harder. Also increase aggresion
79
What do stimulants do?
Speed up reactions, reduce fatigue, increase aggression
80
What do narcotic analgesics do?
Reduce pain, so injuries don't affect performance

Biology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions