Edexcel A level biology Study guides, Class notes & Summaries

Solvent - Answer Substances dissolve in it e.g. water+++ dipolar - Answer Having a slightly positive charge and negative charge Cohesive - Answer They tend to stick together Cohesion - Answer Attraction between molecules of the same type Which side of the heart carries oxygenated blood? - Answer left Why is the left side of the heart thicker? - Answer Because it carries oxygenated blood Where does blood from the vena cava go to? - Answer Right atrium Where does...

Which stage of aerobic respiration produces 4 molecules of CO2 per glucose? - Answer The Krebs Cycle How is glucose converted into pyruvate in Glycolysis? - Answer Glucose is phosphorylated with ATP and then broken into Gylcerate -3-phosphate. Then it is converted into Pyruvate using NAD producing NADH and ATP. Where does glycolysis occur? - Answer Cytoplasm Why does glycolysis occur in the cytoplasm? - Answer The glucose molecules are too big to fit into the mitochondria but Py...

Cellular respiration - Answer process by which food is broken down to yield ATP, which is used as a source of energy for metabolic reactions Respiratory substrate - Answer the substance oxidised during cellular respiration Aerobic respiration - Answer cellular respiration that takes place in the mitochondria in the presence of oxygen. Stalked particles - Answer structures where ATP production takes place on the inner mitochondrial membrane Reduction - Answer addition of ele...

What are the properties of water? - Answer - cohesion and adhesion - high surface tension - high specific heat capacity - polar solvent - less dense when solid Describe the property: cohesion - Answer - water molecules are polar due to the delta negative oxygen atom and delta positive hydrogen atoms - this polarity allows water molecules to form hydrogen bonds, meaning they stick together What is the importance of cohesion? - Answer - allows water to move up the xylem in tra...

a concept that defines cells as a fundamental unit of structure, function and organisation in all living organisms. - Answer Cell theory a tough outer layer which surrounds some cell types and is made of peptidoglycan in bacteria and cellulose in plants. - Answer Cell wall structures found in the cytoplasm made of microtubules that produce the spindle fibres during mitosis. - Answer Centrioles organelles found in plants and algae which are the site of photosynthesis. - Answer Ch...

A water molecule has an unequal distribution of charge. It is therefore described as being...? - Answer Polar What is a molecule with empirical formula CH2O called? - Answer Carbohydrate Hexose sugar - Answer Mono-saccharide containing six carbon atoms Mono-saccharide - Answer simplest form of carbohydrate, building blocks of disaccharides and polysaccharides Maltose is made up of two of which monosaccharide? - Answer Glucose Give three results of Hydrogen bonding in wat...

The gradual, directional change of a community over time, during which the organisms within an ecosystem change the conditions to allow better adapted organisms to colonise the area, replacing it's current inhabitants. - Answer Succession Occurs in a completely lifeless habitat - Answer Primary succession Occurs in a devastated ecosystem - Answer Secondary succession The endpoint of succession - Answer Climax community The first species to colonise an area, tends to be very ...

Fixed Joint -Answer Skull joint that does not move. Cartilage Joint -Answer Rib joint that does not move. Synovial Joint -Answer A moveable joint which is encased in synovial fluid with cartilage padding at the bone end. E.g. Knees or elbows. Ligament -Answer Connects bone to bone. Tendon -Answer Connects muscle to bone. Ball & Socket Joint -Answer Hip and shoulder joints. Gliding Joint -Answer Vertebrae. Hinge Joint -Answer Elbow. Pivot Joint -Answer Ne...

Which 5 factors are used to determine the time of death of a mammal? - Answer • Extent of decomposition • Stage of succession • Forensic entomology • Body temperature • Degree of muscle contraction. Describe the stages of decomposition. - Answer 1) Autolysis occurs - Enzymes in the gut start to break down the wall of the gut and the surrounding area. As cells die, they release enzymes which help break down tissues. 2) The loss of oxygen in tissues favours the growth of a...

Name 3 ways in which carbohydrates are useful - Answer 1. Energy store 2. Energy source 3. Cellulose (structure) What are all carbohydrates made up of? - Answer Carbon, hydrogen, oxygen What are the three main groups of carbs? - Answer Monosaccharides Disaccharides Polysaccharides What is the general formula for monosaccharides? - Answer (CH2O)n What is the formula fo triose sugars? - Answer C2H603 What is the importance of triose sugars? - Answer Important in mito...