1.12 i) Know the difference between monosaccharides, disaccharides and polysaccharides, including glycogen and starch (amylose and amylopectin). ii) Be able to relate the structures of monosaccharides, disaccharides and polysaccharides to their roles in providing and storing energy

monosaccharide- single sugar unit (CH2O)n - n is number of carbon atoms

• 3-7 carbon atoms , most commonly 6 (hexose sugars) e.g. glucose galactose, fructose
• rapid source of energy- little change required for use in cellular respiration

disaccharide- two single units combined in a condensation reaction

glycosidic bond; forms between two sugar units

polysaccharide- long straight or branched chains of sugar units (3+)

• starch- plants  (amylose + amylopectin) 
• glycogen- polymer of glucose- side branches- insoluble- animals,, fungi, bacteria
• energy store 

condensation reactions: formation of complex molecules (-water)
hydrolysis reactions: splits the molecule (+water)

amylose 
straight chain 200-500 glucose molecules. 1,4 glycosidic bonds between adjacent glucose molecules resultant in spiral shape.
amylopectin 
side branches. 1,6 glycosidic link holding side branch to main chain.

structures related to functions. 
side branches allow molecules to be easily hydrolyzed.
low solubility in water means they do no affect the concentration of water in the cytoplasm.

carbon atoms are numbered from 1 clockwise from the oxygen. e.g maltose has a 1,4 glycosidic bond because it forms between carbon 1 on one molecule, 4 on the other.

dietary fibre - cellulose- indigestible in the human gut - movement of material through digestive tract.

1.8 Be able to analyse and interpret quantitative data on illness and mortality rates to determine health risks, including distinguishing between correlation and causation and recognising conflicting evidence.

1.5 Understand the course of events that leads to atherosclerosis (endothelial dysfunction, inflammatory response, plaque formation, raised blood pressure).

atherosclerosis: disease, where arteries become clogged by fatty deposits (plaque/atheroma)
atheroma: degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue

events that lead to atherosclerosis 

1.  damage to endothelium 
2.  inflammatory response White blood cells and cholesterol move into the wall of the blood vessel
3. plaque formation Calcium salts and fibrous tissue build up causing the atheroma to go hard and to form a plaque
4. raised blood pressure blood vessel is narrower                                                                     

 note: the raised blood pressure can then cause another atheroma.

blood clotting process

1. injury 
2. platelets clump at wound 
3. platelets release thromboplastin 
4. this converts Prothrombin into Thrombin
5. Thrombin then converts soluble fibrinogen into insoluble fibrin

link to CV: atheroma narrows the artery, in addition a blood clot could completely block the blood flow, thus preventing oxygenated blood from providing cells with oxygen- this is CVD

prevention

risk factors:

• smoking 
• high fat diet/overweight
• age
• genetics 
• high cholesterol 
• lack of exercise 
• high blood pressure 

treatment of CVD

antihypertensives good/bad:

dry cough 
drowsy, dizzy, faint
foot swelling 
reduces CVD risk, heart attack stroke

1.4 i) Know the cardiac cycle (atrial systole, ventricular systole and cardiac diastole) and relate the structure and operation of the mammalian heart, including the major blood vessels, to its function. ii) Know how the relationship between heart structure and function can be investigated practically.

the heart 



the right side of the heart is shown on the left of the diagram. The left side is on the right side of diagrams.

the left side- oxygen rich blood (thicker walls)
the right side- deoxygenated blood 

tricuspid- right 
bicuspid- left 

both are also known as atrioventricular valves.

atria- collect blood 
ventricles- pump blood

deoxygenated blood enters the body into the right atrium through the superior vena cava. 
oxygenated blood enters the left atrium from the lungs through the left pulmonary veins  

right atrium contracts to pump blood through the tricuspid valve into the right ventricle
left atrium contracts to pump blood through the tricuspid valve into the left ventricle

right ventricle contracts semilunar valve opens and deoxygenated blood travels to the lungs 

cardiac cycle

diastole: the heart ventricles are relaxed and the heart fills with blood. 
systole: ventricles contract and pump blood to the arteries. 

the events that occur in the first and second diastole phases actually happen at the same time. The same is also true for the events of the first and second systole phases

1st diastole phase
heart is relaxed, atrioventricular valves are open
De-oxygenated blood from the superior and inferior vena cava flows into the right atrium. blood to passes through to the ventricles

1.3 Understand how the structures of blood vessels (capillaries, arteries and veins) relate to their functions.

1.2 Understand the importance of water as a solvent in transport, including its dipole nature.

Water is a polar molecule.it has a slight positive charge on one side and a slight negative charge on the other resulting in a net dipole. This is beneficial in many ways. 

hydrogen bonding holds water molecules together, this is what accounts for water being liquid at normal room temperatures. 

many chemicals, especially hydrophilic ones,  dissolve easily in water making them easy to transport, and water a great solvent. 

non-polar, hydrophobic substances e.g. lipids do not dissolve in water. this enables the transport of lipids in blood.

the specific heat capacity is high, taking 42000 Joules to heat one cm3 of water 1°C. This is because of the hydrogen bonding which requires a lot of energy to break. This maintains a constant body temperature.

1.1 Understand why many animals have a heart and circulation (mass transport to overcome limitations of diffusion in meeting the requirements of organisms).

diffusion: the movement of particles down a concentration gradient.

the larger the surface area to volume ratio the more rapidly particles will diffuse. smaller organisms have a large surface area to volume ratio, as well as a shorter distance for particles to travel this makes diffusion a sufficient transport method to obtain nutrients and excrete waste products.

ref. Ficks law

advantages of a double circulatory system:

blood can pass through areas of the body at different speeds. slowly through regions of gaseous exchange; maximising transfer. Then vigorously around the body; enabling organism to be more active.

maths