IB Biology. Joni Rogan Escuela de Lancaster A.C. Course outline - Theory. 1: The chemistry of life Statistical analysis 2: Cells 3: Genetics 4: 5: Ecology and evolution 6: Human health and physiology. Theory Assessment. Makes up 76% of final grade 3 exam papers: Paper 1- 30 MCQ
Une image / un lien ci-dessous est fourni (tel quel) pour télécharger la présentation
Politique de téléchargement : le contenu du site vous est fourni TEL QUEL pour votre information et votre usage personnel ; il ne peut être vendu, concédé sous licence ni partagé sur d’autres sites sans l’accord de son auteur.Le contenu vous est fourni TEL QUEL, pour votre information et votre usage personnel uniquement.Téléchargez la présentation en cliquant sur ce lien.Lors du téléchargement, si vous ne parvenez pas à télécharger une présentation, l’éditeur a peut-être supprimé le fichier de son serveur.Pendant le téléchargement, si vous ne parvenez pas à obtenir une présentation, le fichier a peut-être été supprimé par l’éditeur.
Course outline - Theory • 1: The chemistry of life • Statistical analysis • 2: Cells • 3: Genetics • 4: 5: Ecology and evolution • 6: Human health and physiology
Theory Assessment • Makes up 76% of final grade • 3 exam papers: • Paper 1- 30 MCQ • Paper 2- data based Qs, Extended response • Paper 3- short answer questions
Course Outline- Practical • Practicals make up 24% of final grade. • The marks are in 2 parts: • Investigations • Group 4 projects
Investigations • Throughout course as fits with theory • You are assessed on 2 examples of each of the following: • Design • Data collection • Concluding • Evaluating
Group 4 Projects • Cross-curricular Science project in small groups (with Chemistry and Physics) • You design and carry out an investigation on a theme • You are marked on: • Manipulative skills • Personal skills
To do well in IB Biology..... • Work hard and learn at home throughout the year • Use the rubrics • Learn the command terms • Take the practical work seriously
Introduction • For each of the following you should be able to: • Describe the properties • Know the general formulae & structure • Understand the role in animals & plants • Water • Carbohydrates • Lipids • Proteins • Nucleic acids
Water • What is it made of? • How is it chemically arranged and held together? • What does this mean for how it behaves? • How is this useful for life?
Water H + O - H + • Water is a polar molecule • It forms weak hydrogen bonds • It remains a liquid over a wide temperature range • Water molecules stick to one another = cohesion (surface tension) • Water molecules stick to other substances = adhesion (capillarity)
Water • It has a high specific heat capacity – so water can maintain a reasonably constant temperature (homeostasis) • It has a high latent heat of vaporisation – so animals use water to cool themselves • It is less dense as a solid (ice)… • … and ice is a poor conductor • Water is a good solvent
Carbohydrates • Contain the elements Carbon Hydrogen & Oxygen • There are 3 types: • Monosaccharides • Disaccharides • Polysaccharides
C C O C C C C Monosacharides • (CH2O)n • If n=3, triose (glyceraldehyde) • If n=5, pentose (fructose, ribose) • If n=6, hexose (glucose, galactose) • Monosaccharides are used for • Energy • Building blocks
Isomerism • They can exist as isomers: & glucose OH OH
Disaccharides • Formed from two monosaccharides • Joined by a glycosidic bond • A condensation reaction: • glucose + glucose maltose • glucose + galactose lactose • glucose + fructose sucrose
C C C C O O C C C C C C C C Condensation reaction OH OH
C C C C O O C C C C C C C C Condensation reaction OH OH
C C C C O O C C C C C C C C Condensation reaction O H2O
C C C C O O C C C C C C C C Condensation reaction 1 4 O A disaccharide 1,4 glycosidic bond
Polysaccharides • Polymers formed from many monosaccharides • Three important examples: • Starch • Glycogen • Cellulose
Amylose -glucose 1,4 glycosidic bonds Spiral structure Amylopectin -glucose 1,4 and some 1,6 glycosidic bonds Branched structure Starch Insoluble store of glucose in plantsformed from two glucose polymers:
Glycogen • Insoluble compact store of glucose in animals • -glucose units • 1,4 and 1,6 glycosidic bonds • Branched structure
O O O O O Cellulose • Structural polysaccharide in plants • -glucose • 1,4 glycosidic bonds • H-bonds link adjacent chains
Lipids • Made up of C, H and O • Can exist as fats, oils and waxes • They are insoluble in water • They are a good source of energy (38kJ/g) • They are poor conductors of heat • Most fats & oils are triglycerides
C O H H C O H H C O H H Triglycerides • Formed by esterification… • …a condensation reaction between 3 fatty acids and glycerol: Glycerol
H H H H H H H C C C C C C C O C H H H H H H H O H Fatty acids • Carboxyl group (-COOH) • attached to a long non-polar hydrocarbon chain (hydrophobic): H A saturated fatty acid (no double bonds)
H H H H H H H H C C C C C C C C H H H H H H H H H O C H C C O H H A monounsaturated fatty acid H H O C C H C C C O H H H A polyunsaturated fatty acid
H H H H C C C C O C O H H C H H H H O C O H H H C O H H Esterification Fatty acid Glycerol
H H H H C C C C O C O H H C H H H H O C O H H H C O H H Esterification Fatty acid Glycerol
H H H H C C C C H H H H Esterification C O H H C O H H O C C O H O H H Fatty acid Glycerol
H H H H C C C C H H H H Esterification C O H H C O H H O C C O H Ester bond O H H water
Esterification • This happens three times to form a triglyceride: glycerol fatty acids
Phospholipids • One fatty acid can be replaced by a polar phosphate group: hydrophilic phosphate glycerol Hydrophobic fatty acids
Functions of lipids • Protection of vital organs • To prevent evaporation in plants & animals • To insulate the body • They form the myelin sheath around some neurones • As a water source (respiration of lipids) • As a component of cell membranes
Research Topics • Hydrogenated fats What are they? What foods are they in? How do your bodies deal with them? Why do some people want them banned? 2) Atkins Diet Why does the diet get people to lose weight? What is the difference between how carbohydrates and fats are stored and metabolised? Why are Doctors worried about people on the diet?
R O H N C C H O H H Proteins • Made from C H O N & sometimes S • Long chains of amino acids • Properties determined by the aa sequence Amino acids • ~20 aa • Glycine R=H • Alanine R=CH3 amine carboxyl
R R O O H H N N C C C C H H O O H H H H Peptide bonding
R R O O H H N N C C C C H H O O H H H H Peptide bonding
H H O Peptide bonding R R O O H H N C C N C C H O H H H Peptide bond A condensation reaction water
R O H N C C H H Peptide bonding R O N C C O H H H A dipeptide
Primary structure • The sequence of aas is known as the primary structure • The aa chain is a polypeptide Secondary structure • H-bonding forms between adjacent aa R groups • This results in the chains folding:
