Bio 160

1. Bio 160 Unit 1-2 Week One- Lecture Two

2. Writing Chemical Formulas • 2 methods • Molecular formula- shows the atoms and their numbers, but not how they are bonded • H2O, C6H12O6 • Structural formula- shows the atoms and their numbers but also gives a “picture” or structural map of how the atoms are bonded together • The sticks represent bonds

3. Organic Compounds • Organic compounds are synthesized by cells and contain carbon atoms • Carbon has 4e- in outer shell, so has a high affinity for bonding covalently • Will bond in single or double bonds • Hydrocarbons- compounds formed with only carbon and hydrogen atoms • Can create long chains of carbon or a carbon skeleton

4. Organic Compounds • Carbon skeleton can contain same number of atoms but be shaped differently, creating an isomer • Each isomer, while made up of the same number of atoms, has its own unique properties because of its shape

5. Organic Compounds • Functional groups- usually only certain areas of an organic molecule participate in bonding. That area is called a functional group • 4 major functional groups important for sustaining life • Hydroxyl- OH • Amino- NH2 • Carbonyl- CO • Carboxyl- COOH

6. Organic Compounds • All 4 groups are highly polar, making them hydrophilic and soluble in water • Water is essential for proper metabolic functioning and this is why • Many biological molecules may contain 2 or more functional groups

7. Organic Compounds • Macromolecules- huge organic chains of molecules • Polymers- large molecule consisting of many similar or identical units • Monomers- stick together to create polymers • Polymers stick together to create macromolecules • 40-50 common monomers, plus a few rare ones create the multitude of different biological molecules

8. Organic Compounds • Reaction types • Dehydration synthesis: the creation of polymers by linking an H of one monomer to an OH of another, liberating water (H2O) in the process • Hydrolysis: the breaking down of macromolecules by adding water, breaking the bonds between monomers, giving an OH on one and giving an H to another

9. 4 classes of macromolecules necessary to life • Carbohydrates • Ranges from small sugar molecules to up to long macromolecules • Monosaccharides- simple sugars usually have an –ose ending • Some ratio of C : H2 : O • Glucose C6H12O6 • Fructose isomer of glucose (has the same number of atoms as glucose but arranged differently) • Glucose is the key sugar for cellular E and the necessary end product of the small intestine digestive system

10. 4 Classes of Macro…cont • Disaccharides-double sugar • Comes from the dehydration synthesis of 2 monosaccharide • Most common is sucrose-table sugar • Fructose + glucose = sucrose • Polysaccharides- “many” sugars • Starch- storage sugar- broken down as needed to be released as glucose • Can be hydrolyzed quickly by digestive system

11. 4 Classes of Macro…cont • Cellulose- forms cell walls of plants • Most abundant compound on earth • Closely resembles starch and glycogen but shaped differently • Fibrils lay side by side and are joined together by hydrogen bonds, forming a tough, fibrous wall • Supports plants and trees • Cannot be hydrolyzed by animals unless they have cellulose hydrolyzing microorganisms in their gut • Does provide “roughage” in diet, but does not give nutrition

12. 4 Classes of Macro…cont • Lipids- Fats • Carbon- hydrogen chains • Non-polar, therefore hydrophobic and will not dissolve in water • Fats are composed of glycerol molecule and a fatty acid molecule • 1 glycerol + 3 fatty acids = 1 triglyceride • Body naturally manufactures triglycerides but when you include too much fat in the diet, body makes more than needed and gets stored in fat cells or free floats in blood • Genetic conditions may cause body to overproduce triglycerides, increasing concentration in the blood

13. 4 Classes of Macro…cont • Unsaturated vs. saturated fats • Fat molecules are chains of carbons • How the H’s arrange around the C’s determines whether fat is saturated or unsaturated • Unsaturated have double bonds so not all C’s have H’s surrounding them. Therefore the molecule cannot tightly pack and can be “broken down” much easier in digestive tract • Remain liquid at room temperature • Plant origins

14. 4 Classes of Macro…cont • Saturated fats contain no double bonds, so every C has H’s around it, saturating it. Molecule becomes tightly packed; hard to break down in system and remains solid at room temperature, mostly animal in origin

15. 4 Classes of Macro…cont • Phospholipids contain an atom of phosphorous and have only 2 fatty acids • Major component of cell membranes • Hydrophobic, protects the cell • Wax- 1 fatty acid linked to an alcohol • Protect surfaces from drying out • Steroids- form carbon rings (non anabolic) • Cholesterol- steroid found in cell membranes and used in the manufacture of other types of steroids

16. 4 Classes of Macro…cont • Proteins- made of chains of amino acids • Several different classes of proteins • Structural- hair, tendon/ ligament fibers • Contractile- muscles • Storage- egg whites (food supply for embryos) • Defensive- antibodies • Transport- hemoglobin- carries O2 • Signal-some hormones carry body messages • Enzyme- control rates of chemical reactions without it being used or changed in any way

17. 4 Classes of Macro…cont • 20 amino acids make up all the different types of proteins • All amino acids contain an amino group, carboxyl group and an R group • 1 • It is the R group that makes each amino acid different

18. 4 Classes of Macro…cont • Amino acids linked by peptide bonds, where the carboxyl group of one links with the amino group N of another in dehydration synthesis, creating the polypeptide bond. • The shape of the protein determines its function • Primary shape- the sequence of amino acids • When shape is altered, the functioning ability of the protein is altered as well • Denaturing- altering of protein • Heat, radiation, freezing, pH, salt

19. 4 Classes of Macro…cont • Nucleic Acids- • Deoxyribonucleic Acid • Contains the genetic material or code of the organism • Determines what proteins need to be made and when. • Made of Nucleotides • A sugar (deoxyribose), a phosphate, and nitrogen base (A, T, G, C) • Shaped in a double helix- (double stranded spiral)- one side is a compliment of the other • Cannot leave the nucleus of the cell • A-T G-C

20. Cells

21. Prokaryote cells vs. Eukaryotes • Prokaryote cells are ancient cells and have no organized nucleus. (Bacteria, Archea) • Its DNA is coiled into a nucleotide region but is not differentiated with membrane • Contain ribosomes, plasma membrane, cytoplasm • Some have a bacterial cell wall outside the plasma membrane and others also have a capsule for protection and adhesion. • May also have pilli and prokaryotic flagella

22. Pro. Vs Euk. cont… • Eukaryotic cells make up all other forms of cells • Evolved from prokaryotic cell relationships • Have highly organized and specialized organelles

23. Eukaryotic Cell Organelles (parts) and functions in brief • Not every cell has every organelle • Plant and animal cells do differ in some ways • Organelles • General Manufacturing function • Nucleus • Ribosomes • Rough endoplasmic reticulum (has ribosomes attached) • Smooth endoplasmic reticulum • Golgi bodies (complex, apparatus)

24. Eukaryotic Cell Organelles cont… • General breakdown function • Lysosomes • Peroxisomes (break down materials using hydrogen peroxide H2O2) • Vacuoles • Energy Processing functions • Mitochondria- found in both plant and animals • Cholorplasts- found in plants and some protists

25. Eukaryotic Cell Organelles cont… • Support, movement, communication functions • Cytoskeleton • Cilia, flagella, centrioles, microfilaments • Cell wall- in plants • Extracellular matrix- in animals • Sticky glycoproteins • Cell junctions • Tight, anchoring, communication • Plants- plasmodesmata (channels between plant cells)