Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Molecules of Life ppt
Document related concepts
Transcript
Chapter 5 The Molecules of Life Water Water – makes up 70% of a cell’s weight –Most intracellular reactions occur in the aqueous environment Water Properties: – Inorganic Molecule – nonliving and does not contain C Ex. H2O – Polar compound – one that has a more positive charge on one side, and a more negative charge on the other – Makes a great solvent; dissolves ions and other polar molecules easily Dissolve Hydrogen Bonds – weak attraction between a molecule with a negative charge (ex oxygen) and a hydrogen atom Cohesion – tendency of the molecules of a substance to stick together Adhesion – attractive force between unlike substances Capillary action – ability to spread through narrow pores or tubes against gravity Water is less dense at lower temperatures Draw on your papers Carbon Compounds Organic Compounds – contain C and living – Exceptions: graphite, diamonds, CO2 – Carbon exhibits bonding power of 4 C Most often bonds with hydrogen, oxygen, nitrogen, or to itself and forms chains Hydrocarbon – long chains composed of hydrogen and carbon Draw the example in your notes Functional group – group of atoms within a molecule that interact with other molecules in a predictable way – Ex. See table Monomer - A single, repeated molecule unit – Ex: a sugar molecule in starch Polymer – complex molecules consisting of repeated monomers Macromolecules – large polymers (starch) Condensation Reaction (dehydration synthesis) – process of bonding two monomers together by the removal of a H2O Hydrolysis – process of breaking apart a complex molecule by the addition of a water molecule The Four Biological Molecules 1. Carbohydrates – organic compound made up of sugar molecules – The most abundant of all biological molecules – Contain C, H, and O Carbohydrates Monosaccharide (simple sugars) – one monomer of sugar – Cannot be hydrolyzed into a smaller unit, C6H12O6 – Ex: Glucose, Fructose, Galactose Isomers – Compounds that have the same exact molecular formula but differ in structure and function Monosaccharide ISOMERS Carbohydrates Disaccharide – two monosaccharides joined together by a condensation reaction forming a double sugar, C12H22O11 – Ex: Sucrose, Maltose, Lactose Polysaccharides – complex carbohydrates made up of many joined monosaccharides – Ex: Cellulose – plants structure – Starch – plants store food – Glycogen – animals store food Lipids 2. Lipids - Fatty hydrocarbon compounds also composed of C,H,O – Fats – lipid molecule that have 3 fatty acid tails attached to a glycerol molecule Saturated – all single bonds therefore carbon is bonded to the maximum number of atoms Unsaturated – double bonds appear therefore carbon is attached to fewer atoms Fats Triglyceride Saturated vs. Unsaturated Lipids Steroids – lipid molecule in which the carbon skeleton forms four fused rings – Ex: hormones, cholesterol, plant poisons Draw a Phospholipid (makes up the cell membrane) Proteins 3. Proteins – a polymer constructed from a set of just 20 kind monomers called amino acids – Most diverse group of the large biological molecules – Ex. Hair, fur, nails Proteins Amino Acids – building blocks of proteins, 20 Structure of an amino acid – Carbon atom – Hydrogen atom – Carboxyl group – Amino group – R group Proteins Peptide bonds – bond that links two amino acids together – Ex: Dipeptide – 2 amino acids joined together – Polypeptide – proteins of three or more amino acids Proteins bend and fold to achieve the correct shape so that they can function Denaturation – loss of normal shape of protein – Heat, pH, other environmental factors Proteins Enzymes – Class of proteins which act as catalysts by speeding up specific metabolic reactions by lowering the activation energy Activation Energy – energy needed for a reaction to occur Substrate – substance acted upon by enzyme Active Site – particular region on an enzyme where a substrate binds Nucleic Acids 4. Nucleic Acids – complex organic molecules made up of monomers of nucleotides – Ex: DNA – Deoxyribonucleic Acid – RNA – Ribonucleic Acid Nucleic Acids Nucleotides – Small organic compound comprised of: – 1. Phosphate group – 2. 5-C sugar (pentose) – ribose or deoxyribose – 3. nitrogen base – adenine, guanine, cytosine, thymine Organic Molecules Flipchart Flipchart Organic Compounds Video Watch the video and answer the questions.
