exchange surfaces

• alkane: -ane

  alkene: -ene

  alcohol: -ol

  carboxylic acid: -oic acid

  ketone: -one

  aldehyde: -al

  ester: -ate

  amine: -amine
• a position isomer: functional group of the molecule in a different position
• chain isomers: same molecular formula but different arrangement of carbon skeleton.
• functional group isomers: same molecular formula but different functional group
• what effects the boiling point of alkanes:

  (increasing): longer chains increase the mr of the molecule, causing stronger intermolecular forces (VDWs).

  (decreasing): branching weakens VDWs as molecule is less densley packed so area that intermolecular forces act on is greater and attraction is decreased.
• catalytic converters:

  oxides of nitrogen and carbon monoxide can be removed from systems- using a rhodium catalyst to make harmful products stable (CO2, N2 or H2O)
• haloalkanes are formed when halogens react with alkanes in the presence of UV light, the halogen bonds are broken and a free radical is produced.
• (chlorination) initiation: halogen-halogen bond broken to produce two free radicals.

  
• (chlorination) propagation: the molecule containing the radical changes through single electron transfer. overall a hydrogen is replaced and the Cl radical is reformed as a catalyst.

  
• both the inner and outer membranes of the nuclear envelope are phospholipid bilayers.
• the nucleoplasm is the semi-solid fluid inside the nucleus, where we find the chromatin and the nucleolus.
• the main role of the nucleolus is to act as the site at which ribosomes are made- it also has secondary roles, such as immobilising proteins and forming signal recognition particles.
• where do transport vesicles form?

  the endoplasmic recticulum
• open circulatory systems are found in insects
• the concentration gradient between blood and cells is also better maintained in double circulatory systems, so substances are exchanged faster
• renal artery+vein:

  1. oxygenated blood flows out of the aorta to the kidneys.
  2. oxygenated blood enters kidney through renal artery
  3. oxygen diffuses out of the blood to be used in the kidney cells and the blood is deoxygenated
  4. deoxygenated blood flows out of the kidneys via the renal vein
• how do arteries stretch:

  • elastic fibres
  • endothelium is folded
• how is the direction of
• arteries split into many smaller vessels called arterioles: they control the direction of blood by contracting and relaxing. arterioles split into capillaries.
• the lumen of the vein is wider than the arteries so blood can flow at low pressure
• veins have a thin muscle wall and there is elastic tissue within it.
• venules are small blood vessels that collect blood coming out of capillaries.
• venules range from around 7 micrometers to 1 millimeter in diameter
• tissue fluid is a combination of oxygen, water and nutrients; it surrounds cells.
• when substances diffuse out of capillaries into the cells, some move into tissue fluid in a process called pressure filtration
• there is high hydrostatic pressure in the capillaries at the entrance to a capillary bed: this is created by a high volume of blood forced through capillaries. this high pressure creates a pressure gradient between the inside and outside of capillaries.
• the movement of fluid out of the capillaries causes the hydrostatic pressure in the capillaries to decrease: this means the hydrostatic pressure in the exit of the capillary is lower than the entrance
• cardiac cycle 1)

  1. blood from lungs flows into left atrium and blood from body flows into the right, simultaneously
  2. atria contract, increasing pressure
  3. blood is forced into ventricles
• ventricular contraction 2)

  1. the atria relax and ventricles contract, increasing their pressure
  2. this pressure shuts the atrioventricular valves so no back flow
  3. the blood forced out into pulmonary artery or aorta.
• relaxation 3)

  1. the blood in the pulmonary artery and aorta is at high pressure, this shuts the semi-lunar valves so no back flow
  2. both atria and ventricles relax, atrioventricular valves reopen
  3. blood flows into ventricles and atria from pulmonary vein and vena cava.