BASIC BIOLOGY BIO 101/4 Objectives: 1.understand that all matters are made up of atom/elements 2. list down the main components of life. 3. how molecules and compounds are formed 4. the unique properties of water, carbon, lipid, and protein
<ul><li>Atoms & Elements. </li></ul><ul><li>*Earth & all lives are made up 92 elements. </li></ul><ul><li>*Element – the simplest substance, could not break into simpler compound by any chemical means. </li></ul><ul><li>*4 main elements made up the life: </li></ul><ul><li>i. Carbon </li></ul><ul><li>ii. Oxygen </li></ul><ul><li>iii. Hydrogen </li></ul><ul><li>iv. Nitrogen </li></ul>
*Other elements: Phosphorus (P), potassium (K), sulphur (S), calcium (Ca), iron (Fe), magnesium (Mg), sodium (Na), and chlorine (Cl). *Each element made up of atom *Compound – 2 or more atoms of diff. elements joined together.
Molecules and Compounds: *covalent bonding *ionic bonding *valency of element shell *organic compound
Carbon * Its special properties: i. tetravalent – hold 4 atoms forming tetrahedron structure, very stable. ii. carbon-carbon bond is very strong – forming a long chain in a single / combined with other atoms. iii.
Water - essential to life, human body consists of 60 - 70% water. - consists of 2 Hydrogen atoms & 1 Oxygen atom forming 2 covalent bonds but not equally shared
– Oxygen has a stronger pull on the ê than the Hydrogen resulting in slightly +ve and –ve regions – polar molecules. Water is a dipolar molecule.
The unique properties of water: - mainly due to its hydrogen bond that tends to stick to each other. i. liquid at RT – 1 water molecule could form H-bond with up to 3 other water molecules ii. Universal solvent – bipolar molecule
iii. surface tension – stronger attraction among water molecules. iv. Ice float on water – water most dense at 4 o C, in liquid the H-bond are constantly formed and reformed but in ice the water molecules form H-bond w/ 3 other water molecules and creates a rigid lattice.
v. adhesion – tendency to wet most surface due to its ability to attract to other molecules – polar property. vi. High specific heat capacity. vii. High latent heat of vaporization – creating cooling effect.
iix. latent heat of fusion – high energy lost to form ice crystals. ix. transparent to sunlight. x. high density xi. Difficult to compress xii. Electric conductor – pure water is poor elec. Conductor but dossolve ions is a good conductor.
The significances of water. i. provides a liquid environment inside cells & aquatic organisms. ii. Chemical reactions & transport medium iii. Surface tension allows aquatic organisms move on it.
iv. High density of water allow aquatic organisms to live under ice during the cool season. v. adhesion allow water to move upward against gravity in a narrow channel (capillary force) – in plants (xylem)
vi. High specific capacity – controlls temperature changes – cellular life. vii. High latent heat vaporization – cooling effect. viii. High latent heat fusion – water slowly to freeze.
ix. Transparent – aquatic plants and microorganisms to photosynthesise. x. High density – allow large animals to survive in it; whale, ice, etc. xi. Hardly compressed – acting as hydrostatic skeleton in certain organisma like worms & turgid.
<ul><li>Turgid – composes of 85% water & could dehydrate up to 3% left. </li></ul>
xii. Participate in many chemical reaction due to its polar properties. xiii. Low viscosity & high tensile strength – move freely in small column and reach high up in a big tree.
Water & pH. * Hydrogen and oxygen atoms of water can dissociate to form protons and hydroxide ions: H 2 O ↔ H + + OH - water proton hydroxide ion - pH is measured based on the concent. of [H + ] in particular solution.
Carbohydrates. -Carbon-containing compounds that supply energy to our body. -contains carbon, hydrogen, & oxygen – C x (H 2 O) y , x & y are variables that could be the same/diff. -eg: table sugar, starch, cellulose, & glycogen
-types of carbohydrates: 1. monosaccharides 2. disaccharides 3. polysaccharides
Monosaccharide -the simple type of sugar – (CH 2 O) n, n = 3 – 7, triose, tetrose, pentose,hexose,heptose - glucose is the best known and most abundant sugar – C 6 H 12 O 6. glucose, fructose, galactose. -glucose has two common isomers: alpha & beta based on the position of its hydroxyl group on C 1
Disaccharides. - two monosaccharides forms disaccharide thru condensation process / water removal - alpha glucoses -> starch} glycosidic beta glucose -> cellulose} bond
eg: maltose -> 2 glucose molecules sucrose -> glucose & fructose lactose -> glucose & galactose -Di/polysaccharides could be broken into its constituents thru hydrolysis . -3 to 10 monosaccharides form oligosaccharide.
Polysaccharides -long chain of monosaccharides linked by glycosidic bond & normally insoluble in water, not sweet. eg. Starch, cellulose, glycogen -the monosaccharides could be joint in many ways; straight, branched, or coiled.
-the properties of polysaccharides are determined by the # and types of monomers and how it jointed. - the monomers are joint thru their hydroxyl groups.
starch - energy storage in plants, formed by alpha glucose units, broken down for respiration - 2 common types; amylose & amylopectin. Amylose – linked by 1-4 glycosidic bond. Amylopectin – linked by both 1-6 & 1-4 glycosidic bonds.
-chloroplast is a type of plastics made up of starch. Glycogen – energy storage in animals. - has more branches than starch (1-6 glycosidic bond), less dense and more soluble, found commonly in liver and muscle cells.
-hydrolysed more rapidly than starch due to its bonding type. Cellulose – major constituent in plants and tougher structure. - formed by beta monomer unit, not readily hydrolyzed by common enzymes. - herbivores have microorganisms producing cellulase to digest cellulose.
-cellulose is permeable to water and other substances to enter/leave plant cells freely. Lignin – complex cellulose impregnated with non-carbohydrate materials lining cell wall/tube like xylem.
Lipid - insoluble compound in water bur dissolve readily in other organic compounds like ethanol, diethyl ether. -common type of lipid is triglycerides made up of fatty acids and glycerols thru condensation process; linked by ester bond
-glycerol is a type of alcohol. Fatty acids – a long hydrocarbon chain w/ acidic carboxyl group. - 1 molecule glycerol could combine w/ 3 mol. of fatty acids; could be the same type or diff. type. -triglycerides: oils (liquid) fats (solids)
-2 types of fatty acids: i. saturated ii.unsaturated the atoms around double-bond C atom could be arranged in cis - or trans -form.
-high # of cis-double bond tend to be liquid and trans-form tends to be solid. Significance of lipids: i. provides more energy due to its higher H-content ii. Heat insulation iii. Shock absorption iv. Buoyancy – aid single-celled aquatic animals to be on the surface.
-phospholipids is a major component of cell membrane and also myelin sheath. - consists of glycerol attached to 2 fatty acids w/ the 3 rd hydroxyl group attach to phosphoric acid make it polar portion. * amphipathic property .
Protein. -large & complex molecules, make up 18% of human body. - thousands types with a unique 3-dimensional structure that enables it to play diverse function in organism life.
7 groups of proteins based on their functions: 1 . enzymes- catalyzes biochemical reaction; breakdown & formation of ATP. 2 . structural proteins- forms parts of animal body; ligament & tendon (collagen)
3 . signal proteins – carry messages around the body; insulin, hormone 4 . contractile proteins – involve in movements of our body; myosin & actin for muscle contraction 5 . storage proteins – eg. Albumin in white yolk
Amino acids. - building block of protein - all a.a have amino and carboxyl groups in their general structure.
-The amino and hydroxyl groups, Hydrogen atom & side chain (R group) are attached by covalent bond to a central carbon atom called α -carbon . R-group could be a single H-atom or a complex ring structure, it could be polar or non-polar. Polar proteins readily dissolve in water/cellular solution – transported easily.
Amino acids are amphoteric ; having both acidic and basic properties, make it a good buffer. 2/more amino acids can be joint together by a peptide bond to form dipeptide/polypeptide.
Protein structure. 4 levels of protein structure: i. primary ii.secondary iii.tertiary iv.quaternary.
Primary structure – a single chain of polypeptide. Secondary – folding/coiling structure due to forces between diff. part of the molecules forming alpha-helix/beta-pleated sheet structure.
Tertiary structure – 3D shape of polypeptide chain & could be classified into 2 groups: i. fibrous protein – insoluble in water & physically tough. It is along polypeptide chain linked together. Ii. Globular protein – tightly folded polypeptide forming spherical shape.
Quaternary structure – consists of more than one polypeptide chain bonded together. eg. Haemoglobin structure – 4 polypeptide chain w/ 2 diff. types; alpha and beta chains.