Lifestyle, Health and Risk

Define causation.

When the change in one variable is responsible for a change in another variable

Define correlation.

When a change in one variable is accompanied by a change in the other.

Why is the difference between correlation and causation important?

Correlation does not mean causation. They may be a 3rd variable providing an impact.

What does this graph show?

Positive correlation

How do hypertensives reduce the risk of CVD?

Decrease blood pressure so the endothelium is less likely to be damaged

How do anticoagulants reduce the risk of CVD?

Reduce blood clotting which reduces the risk of blood vessels being blocked by a clot

How do statins reduce the risk of CVD?

Decrease blood cholesterol levels which reduces risk of an atheroma forming

What are the risks of hypertensives?

Headaches

Drowsiness

Heart palpitations

Swelling of feet and ankles

Persistent cough

What are the risks of anticoagulants?

Rashes

Liver dysfunction

Stomach lining damage

Excessive bleeding in case of injury

What are the risks of statins?

Have to take them long term

Take a while to become effective

Muscle and joint pain

Liver damage

Neurological issues

What is an HDL?

High density lipoprotein

What is an LDL?

Low density lipoprotein

What is the proportion of protein in an HDL?

High

What is the proportion of protein in an LDL?

Low

What is the proportion of cholesterol in an HDL?

Low

What is the proportion of cholesterol in an LDL?

High

What is the type of fat that forms an HDL

Unsaturated

What is the type of fat that forms an LDL

Saturated

What is a lipoprotein?

A protein that transports cholesterol

What is cholesterol used for?

Cell membrane

Forming bile salts

Producing sex and growth hormones

How do LDLs work?

They bind to cell receptors. Cell receptors then become overloaded and cholesterol levels increase

How do HDLs work?

Transport cholesterol to the liver where it is then broken down. Blood cholesterol is lowered and fatty deposits are removed

What is the formula for BMI?

Body mass in kg / height in m²

Give the formula for waist to hip ratio

Waist circumference in cm / hip circumference in cm

Explain why waist to hip ratio is a better measure of obesity and heart disease risk.

Unlike BMI, waist to hip ratio takes into account lean mass and abdominal fat, which is associated with an increased risk of CVD

Explain why obesity increases the risk of CVD

Obesity associated with high blood pressure due to inactivity and bad diet. High blood pressure increases likelihood of endothelium damage which would then cause an inflammatory response. This would then lead to an Athenian which increases the risk of CVD

Explain what is meant by the term energy budget?

The balance between the energy taken in and the energy used during life processes

Describe the consequences of a lifestyle where there is an imbalance between energy taken in and energy used.

If more energy is taken in then used then the excess energy is stored and weight is gained.

If less energy is taken in then used then stored energy is used and weight is lost.

Describe consequences of a lifestyle where energy requirement is less than energy intake. Explain how this links to an increase in the risk of CVD.

Excess energy is stored in the body. This increases cholesterol and therefore blood pressure. This then increases the risk of the endothelium being damaged and causing an inflammatory response. An atheroma then forms which increases the likelihood of CVD

Define BMR

Basal metabolic rate

What is BMR?

The calories that you need each day depending on how much energy your body uses when it is completely at rest

What are the risk factors for CVD?

• Smoking

• Sex

• Inactivity

• Age

• Diet

• Genetics

What risk factors can be controlled?

• Diet

• Smoking

• Inactivity

Which risk factors can’t be controlled?

• Age

• Genetics

• Sex

Why is genetics a risk factor?

You can inherit certain alleles that increase cholesterol production or make you more susceptible to high blood pressure

How does Diet increase risk for CVD?

A diet high in saturated fats increases blood cholesterol levels which increases likelihood of atheroma

A diet high in salt increases blood pressure

How does inactivity increase risk of CVD?

Inactivity can increase blood pressure

How does smoking increase risk of CVD?

Nicotine makes platelets more sticky which increases the likelihood of a blood clot

Carbon monoxide bonds to haemoglobin which reduces oxygen being transported which then increases blood pressure

Reduces antioxidants in the blood which increase likelihood of the endothelium being damaged

How does sex increase the risk of CVD?

Men are at a greater risk due to lower oestrogen levels

How does oestrogen decrease risk of CVD?

Increase levels of HDLs which removes cholesterol circulating in the blood

What is a triglyceride?

A type of fat

What is an ester bond?

A bond that forms when the hydroxyl group of the glycerol binds with the carboxyl group of the fatty acid.

What is a saturated fat?

A fat with only single bonds between the carbons

What is an unsaturated fat?

A fat with at least 1 double bond between the carbons

Draw the structure of an unsaturated fat.

.

Draw the structure of a saturated fat.

.

What does an ester bond look like?

.

Name the products of lipid breakdown

Glycerol and 3 fatty acids

How are triglycerides formed?

Condensation reaction

How are triglycerides broken down?

Hydrolysis reaction

Define glycosidic

A chemical bond, like a covalent bond, that connects a carbohydrate molecule to another group.

What is a condensation reaction?

Joining of molecules where hydroxide and hydrogen ions form water

What is a hydrolysis reaction?

The breaking down of molecules where water forms hydroxide and hydrogen ions

How do monosaccharides react to form disaccharides?

Condensation reaction

How do monosaccharides react to form polysaccharides? Specifically amylose and amylopectin.

By condensation reactions. They can form 1,4 glycosidic bonds or 1,6 glycosidic bonds.

How are polysaccharides/ disaccharides broken down into monosaccharides?

By hydrolysis reaction

What monosaccharides make up sucrose?

Glucose and fructose

What monosaccharides make up lactose?

Glucose and galactose

What monosaccharides make up maltose?

Glucose and glucose

How do two monosaccharides form 1,4 glycosidic bonds?

How do two monosaccharides form a 1,6 glycosidic bond?

What is a monosaccharide?

A simple carbohydrate

What is a disaccharide?

2 carbohydrate molecule

What is a polysaccharide?

More than 2 carbohydrate molecule

Define saccharide

A carbohydrate

What does alpha glucose look like?

How does the structure and properties of starch make it a suitable storage molecule?

Amylose:

• Polymer of alpha glucose

• Has 1,4 glycosidic bonds

• Straight chain molecule

• Forms a helical structure

• Efficient at storing lots of glucose

• Insoluble

• Does not effect the water concentration

Amylopectin:

• Polymer of alpha glucose

• 1,4 and 1,6 bonds

• Highly branched molecule

• Many terminal glucose molecules. Makes it ideal for rapid hydrolysis to release glucose for respiration

• Insoluble- no osmotic effect

Explain how the structure and properties of glycogen makes it a suitable storage molecule

• Polymer of alpha glucose

• 1,4 and 1,6 glycosidic bonds

• Highly branched

• Rapid hydrolysis

• Insoluble- no osmotic effect

• Stored in muscles and liver

Why is it ethically acceptable to use invertebrates in research?

They don’t have a developed CNS so they are less susceptible to pain.

They are abundant.

What did you do to lessen the harm of the daphnia?

• Use cotton wool to immobilise the r daphnia

• Use a truncated pipette to avoid crushing it

• Add pond water to the slide to avoid the daphnia suffocating

What could be a drawback of using Daphnia in experiments?

They may experience stress or pain during the experiment

Why may some people disagree with using daphnia?

They still feel pain

Independent Variable

A range of at least 5 caffeine concentrations

Dependent variable

The heart rate

How would you measure the dependent variable?

Count the beats in 15 seconds then multiply by 4 to get bpm

Control Variables

• Daphnia- use the same daphnia

• Temperature- carry out the practical in the same place. Use an LED lamp

• Time- use the same time for the daphnia to acclimatise

What is the method?

• Place a small piece of cotton wool in the slide

• Place a daphnia on the cotton wool

• Place under the microscope and count the times the heart beats in 15 seconds

• Multiply by 4 to get bpm

• Add a drop of caffeine solution to the daphnia

• Leave for 2 minutes

• Count the beats in 15 seconds. Multiply by 4 for bpm

• Repeat with same caffeine solution and different daphnia 2 more times

• Repeat with 4 more caffeine solutions if different concentrates

Why are daphnia suitable for the practical?

They have a translucent exoskeleton so the heartbeat can be seen and they don’t have a nervous system so won’t feel pain

How would you adapt this method to investigate the effects of the volume of caffeine on the heart rate of a glass frog?

• Immobilise the frog on the slide

• Measure the resting heart rate

• Add the caffeine and leave for the acclimatisation period

• Measure the heart rate with the effect of caffeine

• Repeat with the same and different caffeine concentration solutions

Define risk

The possibility of something bad happening.

Define risk factor

Something that increases the risk

Explain why people’s perception of risk and actual risk factor differ.

Risk can be underestimated if the effects happen in the long term.

It can be overestimated if the risk is unfamiliar, out of our control or has severe consequences.

Define probability

The likelihood that something will happen

Explain how you can evaluate experimental design.

If the conclusion is supported by the features of a good experiment then the experiment is valid.

What are the features of a good study?

• Representative sample

• Controlling variables

• Clear aim

• Sample size

• Valid and reliable results

How can you use standard deviation to state whether there is a significant difference between two mean values?

If the standard deviation between the values doesn’t overlap then there is a significant difference.

How can you ensure results are valid and reliable?

• Repeat the study using the same method

• Use a representative sample

• Control variables that may influence the results

Describe the events in the blood clotting cascade.

• Blood vessel wall damages

• Platelets join to the damaged tissue and each other to form a platelet plug

• Platelets produce thromboplastins

• Thromboplastins convert prothrombin to thrombin with Ca2+ ions and vitamin K

• Thrombin converts fibrinogen to fibrins

• Fibrin produces a mesh that traps red blood cells and forms a clot

Explain how blood clotting can impact blood flow and respiring tissues.

• Blood clot forms in blood

• Narrows lumen of blood vessel

• Restricts blood flow

• Stops transport of oxygen downstream

• Cells downstream don’t get oxygen

• Cells can’t respire and die

Where is prothrombin produced?

In the liver.

What is required for thromboplastin to function?

Ca2+ and Vitamin K from the plasma.

Define fibrin.

Substance that traps red blood cells to form a clot.

Define fibrinogen.

Substance that is converted to fibrin.

What is the clotting cascade.

The process that forms a clot.

What is a heart attack?

• Myocardial Infarction

• When an artery is blocked or restricted and stops transport of oxygen to heart muscles.

Risk factors for atherosclerosis.

• High blood pressure

• Obesity

• High blood cholesterol (dietary factors)

• Smoking

• Inactivity

• Genetic inheritance

How does atherosclerosis develop?

• Endothelium damaged by things such as high blood pressure

• White blood cells respond to site of damage

• Substances in blood like cholesterol get caught by white blood cells and form atheroma

• Calcium salts build up and form a hard plaque

• Arteries harden

• Blood flow restricted, increasing blood pressure

Explain how atherosclerosis can impact blood flow and respiring tissue.

Blood flow restricted by the build up of plaque.

Stops transport of oxygen to cells downstream.

Cells cannot respire due to lack of oxygen.

How is atherosclerosis a positive feedback loop?

• Damage is caused by high blood pressure

• Damage then increases blood pressure

• Blood pressure then further damages arteries

Define atherosclerosis.

The build up of plaque that either fully or partially blocks an artery.