Paper 2 - Summary

What is the function of a red blood cell?

Carries oxygen

Why do red blood cells have a biconcave shape?

Increase surface area so they can carry more oxygen

Why don’t red blood cells have a nucleus?

More space to carry oxygen

What is the red pigment in red blood cells called?

Haemoglobin

What element does haemoglobin contain?

Iron

What is the function of haemoglobin?

Oxygen binds to it

What is the haemoglobin called when it is carrying oxygen?

Oxyhaemoglobin

What is the haemoglobin called when it is not carrying oxygen?

Deoxyhaemoglobin

What is the function of platelets in the blood?

Clot blood

Name the liquid part of the blood that everything else floats in.

Plasma

What are the substances carried in the blood?

* Oxygen
* Glucose
* Amino acids
* Carbon dioxide
* Hormones
* Urea
* Protein

Which blood vessels carry blood away from the heart?

Arteries

Is the blood under high or low pressure in the artery?

High

Why do arteries contain thick layers of muscle?

Strengthen them

Why do arteries contain elastic fibres?

To allow recoil

Which blood vessels carry substances to the organs?

Capillaries

Why are capillaries narrow?

They can squeeze between the gaps between cells (every cell gets substances)

Why do capillaries have permeable walls?

So substances can diffuse in and out

How many cells thick is a capillary wall?

1

Which substances are carried to cells in capillaries?

* Oxygen
* Glucose
* Amino acids

What substances are removed from cells by capillaries?

* Carbon dioxide
* Urea

Which blood vessels carry blood back to the heart?

Veins

Is blood pressure high or low in the veins?

Low

Why do veins have valves?

Prevent backflow

Do veins have a small or big lumen?

Big

Why do veins have a big lumen?

Helps blood flow

What is a double circulatory system?

Heart pumps blood to the lungs and to the rest of the body

Where does the right side of the heart pump blood to?

Lungs

Which specific blood vessel carries blood from:

heart → lungs

Pulmonary artery

Which specific blood vessel carries blood from:

lungs → heart

Pulmonary vein

Which specific blood vessel carries blood from:

heart → organs

Aorta

Is the aorta a vein or an artery?

Artery

Which specific blood vessel carries blood from:

organs → heart

Vena cava

Is the vena cava a vein or an artery?

Vein

When blood goes:

pulmonary vein → heart

Which part of the heart does it enter after?

Left atrium

Where does blood flow to after the left atrium?

Left ventricle

What does blood pass through in between:

left atrium → left ventricle

Atrio-ventricular (AV) valves

Which blood vessel does the blood enter after the left ventricle?

Aorta

What does blood pass through in between:

ventricle → artery

Semi-lunar valves

What blood vessels does blood enter when it passes through the organs?

Capillaries

Which substances transfer to cells from the blood inside the capillaries?

* Oxygen
* Glucose
* Amino acids

Which substances leave cells and go into the capillaries?

* Carbon dioxide
* Water
* Urea (from liver)

Which blood vessel does blood enter when:

capillaries → heart

Vena cava

Where does the blood go after the vena cava?

Right atrium

Where does blood flow after the right atrium?

Right ventricle

Where does blood flow after the right ventricle?

Pulmonary artery

Which side of the heart has a thicker wall?

LeftWh

Why does the left side of the heart have a thicker wall than the right?

Blood needs to be pumped a further distance, so it is pumped at a higher pressure

What is cardiac output?

Volume of blood pumped out the heart per minute

What is the equation for cardiac output?

heart rate (bpm) × stroke volume

Why do organs need glucose and oxygen?

Aerobic respiration

What is the word equation for aerobic respiration?

oxygen + glucose → carbon dioxide + water + energy

What is the balanced, symbol equation for aerobic respiration?

6O₂ + C₆H₁₂O₆ → 6CO₂ +6H₂O + energy

Is energy made or released during respiration?

Released

Where does aerobic respiration take place in the cells?

Mitochondria

Which type of cells contract during exercise?

Muscle cells

What do muscle cells use in order to contract?

Energy

What process releases energy inside muscle cells?

Aerobic respiration

What substances do muscle cells need in order to respire?

* Oxygen
* Glucose

What is this piece of equipment called?

Respirometer

What is this piece of equipment used for?

Measuring respiration rate

What gas will the insects be using when respiring in the tube?

Oxygen

What gas will the insects be producing when respiring in the tube?

Carbon dioxide

Which chemical absorbs carbon dioxide so that we can identify how much oxygen the insects are using up during this experiment?

Sodium hydroxide

Which direction will the liquid move when the insects use up oxygen?

Left

What is the equation for the rate that the liquid moves during the experiment?

distance ÷ time

How should you ensure the insect’s safety when using a respirometer?

Don’t leave them in the tube too long (or they will run out of oxygen and die)

Which type of exercise results in muscle cells not being supplied with enough oxygen?

Vigorous exercise

What type of respiration do muscle cells do when they don’t have enough oxygen?

Anaerobic

What is the word equation for anaerobic respiration?

glucose → lactic acid

What does a build-up of lactic acid cause?

Cramps

Do plants carry out respiration?

Yes

Why do plants have mitochondria?

Aerobic respiration

Are there times when plant cells do not get enough oxygen?

Yes

What type of respiration do plants do when they don’t get enough oxygen?

Anaerobic respiration

What is the word equation for anaerobic respiration in plants?

glucose → ethanol + carbon dioxide

Which organ monitors the concentration of glucose in the blood?

Pancreas

What hormone is released by the pancreas when the blood glucose concentration is higher than normal?

Insulin

Name the target organ/cells for insulin.

* Liver
* Muscle cells

How does insulin travel to the liver and muscle cells?

Blood

What does the liver do in response to insulin?

Takes it and stores it as glycogen

What hormone is released by the pancreas when blood glucose concentration is lower than normal?

Glucagon

Name the target organ for glucagon.

Liver

What does the liver do in response to the glucagon?

Breaks down glycogen back into glucose and puts it back into the blood

What else is the pancreas referred to as?

Endocrine gland

What causes type 1 diabetes?

Pancreas cannot make insulin

What is the main treatment for type 1 diabetes?

Insulin injections

Where is insulin injected into when someone has type 1 diabetes?

Subcutaneous fat

What are changes in lifestyle people with type 1 diabetes can make?

* Eat more complex carbohydrates
* Exercise regularly

What causes type 2 diabetes?

Liver and muscle cells aren’t as responsive to insulin

Can obesity cause type 2 diabetes?

Yes

What is the equation for BMI?

weight ÷ height

How does waist-to-hip ratio contribute to type 2 diabetes?

Ratio above 1.0 for men and 0.85 for women linked to increased risk

What is the equation for waist-to-hip ratio?

waist circumference ÷ hip circumference

State 2 treatments for type 2 diabetes?

* Healthy diet
* Regular exercise

Do some people with type 2 diabetes inject insulin?

Yes

State the endocrine for thyroxine.

Thyroid gland

How does thyroxine concentration affect metabolic rate?

As thyroxine concentration increases, metabolic rate increases

Which part of the brain monitors the concentration of thyroxine in the blood?

Hypothalamus

What hormone does hypothalamus release when thyroxine concentration is lower than normal?

TRH