Carbon Compounds in Cells

1. Carbon Compounds in Cells Chapter 3

2. Organic Compounds Organic compounds: molecules containing both Carbon (C) and hydrogen (H) Four main types of carbon containing molecules found in cells: Carbohydrates Lipids Proteins Nucleic Acids

3. Carbon�s Bonding Behavior Carbon atoms share pairs of electrons with as many as 4 other atoms Carbon can form strings or rings of carbon with special molecular groups attached

4. Bonding Arrangements Carbon atoms can form chains or rings Other atoms project from the carbon backbone

5. Functional Groups Atoms or clusters of atoms that are covalently bonded to carbon backbone Give organic compounds their different properties

6. Examples of Functional Groups Methyl group - CH3 Hydroxyl group - OH Amino group - NH3+ Carboxyl group - COOH Phosphate group - PO42- Sulfhydryl group - SH

7. How are organic molecules built? Functional Group Transfer Electron Transfer Rearrangement Condensation Cleavage

8. Condensation Reactions Dehydration Synthesis Combine 2 molecules into 1 via covalent bonds. Occurs during polymerization, attachment of monomers into a chain called a polymer Enzymes remove -OH from one molecule, H from another, form bond between two molecules

9. Cleavage Split 1 molecule into 2 smaller molecules Hydrolysis A type of cleavage reaction; condensation in reverse Breaks polymers into smaller units:

10. Polymers Monomer: One unit Polymers: Many units

11. Carbohydrates (sugars) Carbon:Hydrogen:Oxygen ratio of 1:2:1 (CH2O)n End in �-ose� Types: Monosaccharides (simple sugars) Oligosaccharides (short-chain carbohydrates) Disaccharides Polysaccharides (complex carbohydrates)

12. Monosaccharides Simplest carbohydrates Most are sweet tasting, water soluble Most have 5- or 6-carbon backbone, form rings Examples Glucose, Fructose, Galactose

13. Disaccharides (Oligosaccharides) Two monosaccharides covalently bonded Formed by condensation reaction Examples: Sucrose: Glucose + fructose Maltose: Glucose + Glucose Lactose: Glucose + Galactose

14. Polysaccharides Straight or branched chains of many sugar monomers (Usually glucose) Examples: Starch - Energy storage in Plants Glycogen - Energy storage in Animals Cellulose - Cell wall in plants Chitin - Cell wall in fungi

15. Polysaccharides

16. Hydrocarbons with little or no affinity to water Basic unit of most lipids is the Fatty Acid: Lipids

17. Fatty Acids Saturated fatty acids contain only single bonds Found in animal fats and usually solid Unsaturated fatty acids contain double bonds Found in plants and are liquid

18. Triglycerides (Fat) 3 Fatty acid attached to glycerol Body�s most abundant lipids Stored as droplets in fat cells

19. Phospholipids Glycerol backbone, 2 fatty acids, and a phosphate-containing hydrophilic head Main component of cell membranes

20. Sterols and Derivatives No fatty acids Rigid backbone of four fused-together carbon rings Examples: Cholesterol most common type in animals Steroids (Sex Hormones) Bile Salts

21. Waxes Long-chain fatty acids linked to long-chain alcohols or carbon rings Firm consistency, repel water Important in water-proofing

22. Proteins (Peptides) Amino Acids: building blocks of proteins Small organic compounds containing an amino group and a carboxyl group 20 different amino acids are incorporated into proteins. They differ by having unique R-groups. These R-group give each amino acid particular properties.

23. Amino Acid Structure

24. Amino Acids

25. Amino Acids

26. Protein Synthesis Amino acids are joined by peptide bonds to form proteins Peptide Bond: A covalent bond between one amino acid�s Carboxyl group and Amino group of another Formed by dehydration synthesis

27. Protein-related definitions Dipeptide � two amino acids held by peptide bond Polypeptide � many a.a. held together by peptide bonds Protein � One or more polypeptide(s) that perform a specific function

28. Protein Functions ENZYMES Structure (e.g. Collagen) Transport (e.g. Hemoglobin) Immunity (e.g. Antibodies) Motor (e.g. myosin in muscles cells) Receptor proteins (e.g. rhodopsin in eyes) Regulatory (e.g. hormones)

29. Protein Structure The structure of proteins is fundamental for their function (i.e. what they look like determines what they can do) Proteins have four levels of structure: Primary (1�) Secondary (2�) Tertiary (3�) Quaternary (4�)

30. Levels of Protein Structure

31. Primary Structure Sequence of amino acids joined by peptide bonds This sequence dictates the shape of a protein Unique for each protein Example:

32. Secondary Structure Regular folding patterns created by hydrogen-bonding of polypeptide backbone Either Alpha Helix or Beta Pleated Sheets

33. Tertiary Structure 3D structure of polypeptide chain Determined by various interactions between side chains H-bonds Disulfide bridges (covalent) Ionic bonds Hydrophobic interactions

34. Quaternary Structure Interaction between more than one tertiary folded proteins

35. The 3? & 4? structures create proteins that are either: Globular: Folded in a round shape E.g. Hemoglobin Fibrous: Long strand or sheets E.g.Keratin, Collagen Protein Structure

36. Special Proteins Glycoproteins: Proteins with sugars attached to one end. Found on the surface of cells Lipoproteins: Proteins bound to lipids. Blood proteins that bind to cholesterol, triglycerides, phospholipids

37. Nucleic Acids Two main types (polymer): Ribonucleic Acid (RNA) Deoxyribonucleic Acid (DNA) Nucleic acids are made of Nucleotides (monomers)

38. Basic units of DNA and RNA Energy carriers (ATP) Coenzymes (NAD+, FAD) Chemical messengers (cAMP) Nucleotides

39. Nucleotide Structure 5-Carbon Sugar: Deoxyribose or Ribose Base: Adenine (A), Guanine (G), Thymine (T), Cytosine (C), or Uracil (U) Phosphate: 1 to 3 groups linked together

40. Deoxyribonucleic Acid

41. Composition of a Cell