Topic 7 - run for your life

Question 2

What are tendons?

Answer 2

Non-elastic tissue which connects muscles to bones.

Question 3

What are ligaments?

Answer 3

Elastic tissue that joins bones together and determines the amount of movement possible at a joint.

Question 4

What are joints?

Answer 4

The area where two bones are attached for the purpose of permitting body parts to move. They’re made of fibrous connective tissue and cartilage.

Question 5

What are skeletal muscles?

Answer 5

Muscles attached to bones, arranged in antagonistic pairs.

Question 6

What are antagonistic muscle pairs?

Answer 6

Pairs of muscles which pull in opposite directions. As one muscle contracts, the other relaxes.

For example, triceps and biceps in the arm: when the triceps relaxes, the biceps contracts to lift the arm.

Question 7

What is the first step in muscle contraction according to the Sliding Filament Theory?

Answer 7

Calcium ions are released from the sarcoplasmic reticulum upon nervous stimulation and bind to the troponin molecule, changing its shape.

Question 8

What happens after calcium ions bind to troponin?

Answer 8

Myosin binding sites are exposed, and the head moves forward to form an actomyosin bridge.

Question 9

What occurs after the actomyosin bridge is formed?

Answer 9

ADP + Pi is released, and the myosin head moves forwards, shortening the sarcolemma.

Question 10

What happens when free ATP binds to the myosin head?

Answer 10

The myosin head changes shape, moving back to its original position.

Question 11

What role does ATPase play in muscle contraction?

Answer 11

ATPase in the myosin head breaks ATP back into ADP + Pi to restore the original state.

Question 12

What happens with repeated stimulation during muscle contraction?

Answer 12

Continued contraction occurs. If stimulation is stopped, ATP released is used to actively transport calcium ions back into the sarcoplasmic reticulum.

Question 13

Process of sliding filament theory

Answer 13

1. Calcium ions released from sarcoplasmic reticulum upon nervous stimulation. Bind to troponin molecule - changing its shape.
2. Myosin binding sites exposed, head moves forward to form an actomyosin bridge.
3. ADP + Pi released, myosin head moves forwards - shortening the sarcolemma.
4. Free ATP binds, myosin head changes shape - moving back to original position.
5. ATPase in myosin head breaks ATP back into ADP + Pi to restore the original state.
6. Repeated stimulation causes continued contraction. If stimulation is stopped, ATP released is used to actively transport calcium ions back into sarcoplasmic reticulum.

Question 14

What are the four stages of aerobic respiration?

Answer 14

• Glycolysis
• Link Reaction
• Kreb’s Cycle
• Oxidative Phosphorylation

Each stage plays a crucial role in the overall process of aerobic respiration.

Question 15

Where does glycolysis occur?

Answer 15

In the cytoplasm

Glycolysis is the first step in both aerobic and anaerobic respiration.

Question 16

What are the products of glycolysis?

Answer 16

• 2 molecules of pyruvate
• 2 molecules of ATP
• 2 molecules of NADH

These products are essential for subsequent stages of respiration.

Question 17

What happens to pyruvate in anaerobic respiration?

Answer 17

It is reduced into lactate

This reduction is facilitated by NADH, and lactate must be oxidized back to pyruvate in the liver.

Question 18

What is the consequence of lactate accumulation?

Answer 18

It creates an oxygen debt and decreases blood pH

Lowered pH can affect enzyme activity and lead to muscle fatigue.

Question 19

What is produced during the link reaction?

Answer 19

Acetyl coenzyme A and NADH

Pyruvate binds to coenzyme A in this reaction.

Question 20

What is the first compound formed in the Krebs cycle?

Answer 20

Citrate

Citrate is formed when acetyl-CoA donates 2 carbons to oxaloacetate.

Question 21

What are the products of the Krebs cycle?

Answer 21

• Carbon dioxide
• ATP
• Reduced NAD
• Reduced FAD

The cycle involves oxidation of citrate and restoration of CoA.

Question 22

Fill in the blank: Glycolysis produces _____ molecules of ATP.

Answer 22

2

This is one of the key outputs of glycolysis.

Question 23

True or False: Glycolysis occurs in the mitochondria.

Answer 23

False

Glycolysis occurs in the cytoplasm, not in the mitochondria.

Question 25

What is oxidative phosphorylation?

Answer 25

The process in which ATP is synthesised via chemiosmosis in the electron transport chain in mitochondria ## Footnote This process generates the majority of ATP in aerobic respiration.

Question 26

What occurs during the redox reactions in oxidative phosphorylation?

Answer 26

Electrons are carried from one electron carrier to another, where the electron carrier that passes the electron is oxidised and the one that receives it is reduced.

Question 27

What happens to hydrogen ions during oxidative phosphorylation?

Answer 27

Hydrogen ions are actively transported across the membrane into the intermembrane space using the energy from redox reactions.

Question 28

What is the result of hydrogen ion transport in oxidative phosphorylation?

Answer 28

The concentration of hydrogen ions in the intermembrane space is high.

Question 29

How do hydrogen ions return to the mitochondrial matrix?

Answer 29

Hydrogen ions diffuse back into the mitochondrial matrix down the electrochemical gradient through the protein ATP synthase.

Question 30

What is produced on stalked particles using ATP synthase?

Answer 30

ATP.

Question 31

What do hydrogen ions and electrons combine with to produce water?

Answer 31

Oxygen.

Question 33

What is the term for the heart's ability to initiate its own contraction?

Answer 33

Myogenic ## Footnote Myogenic refers to the heart's ability to generate its own electrical impulses.

Question 34

Where does depolarisation originate in the heart?

Answer 34

Sinoatrial Node ## Footnote The Sinoatrial Node is often referred to as the natural pacemaker of the heart.

Question 35

What happens to the atria during depolarisation?

Answer 35

Causing atrial systole ## Footnote Atrial systole is the contraction of the atria that pushes blood into the ventricles.

Question 36

What structure splits into two branches after the Bundle of His?

Answer 36

Bundle of His ## Footnote The Bundle of His conducts electrical impulses from the AV node to the ventricles.

Question 37

What prevents depolarisation from spreading directly to the ventricles?

Answer 37

Annulus fibrosus ## Footnote The annulus fibrosus is a fibrous ring that electrically isolates the atria from the ventricles.

Question 38

What region of conducting tissue is stimulated after the annulus fibrosus?

Answer 38

Atrioventricular Node ## Footnote The Atrioventricular Node helps regulate the timing of ventricular contraction.

Question 39

What occurs between atrial systole and ventricular systole?

Answer 39

A slight delay ## Footnote This delay allows the ventricles to fill with blood before they contract.

Question 40

What conducts depolarisation into the ventricles after the AVN?

Answer 40

Bundle of His and Purkyne Fibres ## Footnote Purkyne Fibres distribute the electrical impulse throughout the ventricles.

Question 41

What does an electrocardiogram (ECG) measure?

Answer 41

Spread of a wave of depolarisation ## Footnote The ECG provides a visual representation of the heart's electrical activity.

Question 43

What is the formula for calculating cardiac output?

Answer 43

Cardiac output = stroke volume x heart rate ## Footnote Cardiac output is a measure of the heart's efficiency in pumping blood.

Question 44

How can cardiac output be regulated? glucose is phosphorylated to produce 2 molecules of pyruvate, 2 molecules of ATP and 2 molecules of NADH.

Answer 44

By controlling the heart rate ## Footnote Adjusting the heart rate can influence how much blood is pumped per minute.

Question 45

Summarise glycolysis

Answer 45

glucose is phosphorylated to produce 2 molecules of pyruvate, 2 molecules of ATP and 2 molecules of NADH.