| what is energy balance? | the balance of calorie intake compared to calories burned due to physical activity |
| why is energy balance important? | humans need the right amount of calorie intake so that they do not become underweight or overweight and therefore be prone to sicknesses and disease |
| what does it mean when someone is underweight? | the calorie intake is less than the calories burned |
| factors that show someone is underweight | weakened immune system
fragile bones
feeling tired
growth and development issues
malnutrition
fertility issues due to irregular menstrual cycles (in women) |
| what does it mean to be overweight? | calorie intake is more than the calories burned |
| factors that show someone is overweight | breathing problems
diseases such as cancer, type 2 diabetes and arthritis
high cholesterol
high blood pressure
hardened arteries |
| `weight gain | when excess calories taken in are stored as fats |
| monosaccharides | single sugar units
alpha/beta glucose |
| disaccharides | 2 single sugar units joined by glycosidic bond through a condensation reaction
maltose = glucose + glucose
lactose = glucose + galactose
sucrose = glucose + fructose |
| polysaccharides | long chain of glucose molecules made up of monosaccharides joined by glycosidic bonds
starch, amylose, amylopectin, cellulose, glycogen |
| difference between starch and glycogen | starch is found in plants, glycogen is found in animals
glycogen is made up of only one polymer
starch is made up of two polymers - amylose and amylopectin |
| similarities between starch and glycogen | both made of alpha glucose
both are branched so both contain 1-4 and 1-6 glycosidic bonds
both are energy stores
both are compact and insoluble |
| differences between amylose and amylopectin | amylose is straight chain whilst amylopectin is branched
amylose has only 1-4 bonds but amylopectin has 1-4 and 1-6 bonds |
| similarities between amylose and amylopectin | both make up starch
both are made of alpha glucose
both have 1-4 glycosidic bonds
both are polysaccharides |
| how do monosaccharides join to form polysaccharides? | a condensation reaction occurs
water is released
glycosidic bond forms between the OH groups on each monosaccharide |
| how do polysaccharides split up? | hydrolysis reaction
water is added |
| what is a triglyceride? | a type of fat found in the blood
stores energy
made up of 3 fatty acids and 1 glycerol |
| what bond forms to make triglycerides? | ester bonds form between the glycerol and the fatty acids |
| what is the difference between saturated and unsaturated lipids? | saturated don't have a carbon-carbon double bond but unsaturated do
saturated lipids are solid at room temp whilst unsaturated are liquid at room temp due to weaker intermolecular forces |
| what is cholesterol? | a soluble lipid that is transported around the body by lipoproteins |
| what are HDLs? | high density lipoproteins
'good cholesterol'
transports cholesterol from the body tissues to the liver the be broken down
reduces cholesterol levels in the blood therefore reducing the risk of atherosclerosis |
| what are LDLs? | low density lipoproteins
'bad cholesterol'
transports cholesterol from the liver to the blood
increases blood cholesterol levels therefore increases the risk of atherosclerosis |
| why is there a causal relationship between cholesterol and risk of CVD? | increased risk of plaque formation
arteries become hardened and narrower
this reduces the flow of oxygenated blood to the cardiac cells
cells cant respire and die causing a CVD |
| why does saturated lipids and high blood cholesterol correlate? | saturated lipids make up low density lipoproteins
more LDL means more cholesterol in the blood |
| obesity indicators | BMR - basal metabolic rate
BMI - body mass index
waist to hip ratio |
| how does BMR measure obesity? | calculates the minimum amount of calories your body needs to function at rest |
| how does BMI measure obesity? | BMI = Weight (kg)/Height² (m) |
| how does waist to hip ratio measure obesity? | compares the waist size to the hip size
larger waist to hip ratio signifies obesity |
| what factors affect the risk of developing CHD? | diet
exercise
smoking |
| what is CHD? | coronary heart disease |
| how can diet reduce the risk of developing CHD? | reduced cholesterol, sat fats and salts
more fruits and veg that contain fibres and antioxidants
less build up in arteries so less risk of damage to the endothelium
reduced risk of atherosclerosis and eventually CHD |
| how can exercise reduce the risk of developing CHD? | this reduces fat stores
less risk of atherosclerosis therefore less risk of CHD |
| how can stopping smoking reduce the risk of developing CHD? | lumen will be wider
therefore less high pressure generated in the artery
reduces the risk of endothelial damage therefore reduced risk of atherosclerosis then CHD |
| daphnia experiment | measures the effect of caffeine on heart rate
daphnia placed under microscope in pro-slow solution
5 different concentrations of caffeine used
allow daphnia to acclimatise for about 2 mins before carrying out experiment
count how many heart beats using a clicker for 1 min
do repeats to get the mean heart rate
make sure all daphnia used are the same age and same source |
| ethical issues regarding the use of invertebrates | although invertebrates will not feel pain whilst carrying out the experiment they are still living organisms so some may not like the idea of testing on living creatures |
| vitamin C experiment | 5 different juices with one being vitamin C solution
carefully titrate each juice into dcpip solution
swirl around to get a colour change of blue to light pink/colourless
record results
repeat to get mean averages |
| what treatments are available for CVD? | antihypertensives: beta blockers, diuretics, ACE inhibitors
anticoagulant
statins
platelet inhibitors |
| benefits and side effects of beta blockers | benefits: reduced frequency of heart contractions
side effects: higher risk of diabetes |
| benefits and side effects of antihypertensive medication | benefit: reduces blood pressure
side effects: dizziness, arrhythmia, nausea |
| benefits and side effects of diuretics | benefits: increases volume of urine reducing blood volume
side effects: nausea, muscle cramps, diziness |
| benefits and side effects of ACE inhibitors | benefits: reduces atrial constriction therefore reducing blood pressure
side effects: dizziness, cough, heart arrhythmia |
| benefits and side effects of anticoagulants | benefits: reduce the formation of blood clots
side effects: excessive bleeding |
| benefits and side effects of statins | benefits: reduces blood cholesterol by blocking cholesterol producing enzyme in the liver
side effects: nausea, constipation, muscle pain, increased risk of diabetes, headache |
| benefits and side effects of platelet inhibitors | benefits: reduces the formation of blood clots by making platelets less sticky
side effects: excessive bleeding |
