The Food Groups: Food Group Function Lipids (fats & oils) Used as a long-term energy (much easier to store than carbohydrates). Also have a role in protection and insulation Carbohydrates Made from single sugars or chains of sugars. They are used in respiration to provide energy. Proteins Broken down into amino acids, which our body absorbs and assembles into new proteins. The proteins are used for growth and repair. Fibre Regulates bowel movement. Sloughs off old lining of intestine. Water Essential as a solvent for chemical reactions (e.g. cytoplasm), heat loss (e.g. transpiration), transport (e.g. blood) etc Vitamins and Minerals Essential for the normal function of some enzymes and proteins e.g. Fe2+ is an essential part of Haemoglobin and Mg2+ is part of Chlorophyll Components of the main Food Groups: The main food groups are carbohydrates, lipids and proteins. All three groups are made from smaller molecules. Carbohydrates are large molecules made from one or more sugars (e.g. both Starch and Glycogen are both polymers of Glucose) Proteins are polymers of Amino Acids Lipids are made from one glycerol molecule and three fatty acid molecules joined together.
Photoreceptors detect Reflex occurs Muscles in the Iris are the effectors Radial muscles in Iris contract Circulatory muscles in Iris relax Pupil diameter opens More light enters the eye Photoreceptors detect Reflex occurs Muscles in the Iris are the effectors Radial muscles in Iris relax Circulatory muscles in Iris contract Pupil diameter closes Less enters the eye Focusing the eye: Far Object Near Object Incoming light is parallel Ciliary muscles relax Suspensory ligaments are tight Lens is pulled thin is refracted less Light converges on the retina Incoming light is divergent Ciliary muscles contract Suspensory ligaments are loose Lens becomes fat Light is refracted more Light converges on the retina Controlling Skin temperature: Too hot Too cold
Cell Division: There are two types of cell division; Mitosis – used for growth, repair & asexual reproduction Meiosis – used to produce gametes for sexual reproduction Mitosis Meiosis Produces 2 daughter cells Daughter cells are diploid (i.e. only have 23 chromosomes) Daughter cells are genetically identical to each other Daughter cells are genetically identical to parent cell Occurs in one stage Happens everywhere in the body Produces 4 gametes Daughter cells are haploid (i.e. have 23 pairs of chromosomes) Gametes are genetically different to each other Gametes are genetically different to parent cell Occurs in two stages Happens in reproductive organs only Therefore, fertilization produces a diploid cell will grow by mitosis) from two haploid gametes.
A Fermenter: Important details: Cooling jacket – keeps the microorganisms at optimum temperature. They will produce lots of heat through respiration, therefore need to be cooled! Paddles – keep stirring the mixture. This stops waste products from building up and keeps the air evenly mixed Nutrient medium – supplies the microorganisms with fuel for respiration Sterile Air supply – supplies clean O2 for respiration (note: this is not required in anaerobic fermentation processes) Data-logger – monitors temperature and pH, keeps the fermenter at optimum conditions You don’t need to be able to draw this out, but you could be asked to label a diagram of a fermenter or be asked to explain the function of the various parts of a fermenter.