Carbohydrates, Lipids and Proteins (Biological Building blocks)

1. Carbohydrates, Lipids and Proteins(Biological Building blocks) IB Biology – Assessment Statements 3.2.1 to 3.2.7

2. Chemistry of Life • Organic chemistryis the study of carbon compounds • Carbon atoms are versatile building blocks • bonding properties • 4 stable covalent bonds

3. Organic and Inorganic Compounds • Organic compounds contain carbon (C) and occur naturally only in the bodies of living organisms. • They almost always contain hydrogen (H), usually contain oxygen (O) and nitrogen (N), • Sometimes contain phosphate (P), sulfur (S), iron (Fe), copper (Cu), sodium (Na), chlorine (Cl) or potassium (K) in small amounts. Assessment Statement 3.2.1

4. Organic and Inorganic Compounds • Inorganic compounds do not usually contain carbon. This term is used when referring to any compound that is not organic. http://www.slideshare.net/gurustip/organic-or-inorganic-presentation Assessment Statement 3.2.1

5. Organic and Inorganic Compounds • Carbon molecules can form long chains or rings. Allowing for multiple branches for bonding. • The size and arrangement of organic compounds are unlimited. • Organic compounds are divided into 4 groups: • Carbohydrates • Lipids • Proteins • Nucleic acids. Assessment Statement 3.2.1

6. Complex molecules can be assembled like building blocks.

7. Hydrocarbons can grow…

8. Isomers • Molecules with same molecular formula but different structures (shapes) • different chemical properties • different biological functions 6 carbons 6 carbons 6 carbons

9. Identify amino acids

10. Form affects function • Structural differences create important functional significance • amino acid alanine • L-alanine used in proteins • but not D-alanine • medicines • L-version active • but not D-version • sometimes withtragic results… stereoisomers

11. Form affects function • Thalidomide • prescribed to pregnant women in 50s & 60s • reduced morning sickness, but… • stereoisomer caused severe birth defects

12. Viva la difference! • Basic structure of male & female hormones is identical • identical carbon skeleton • attachment of different functional groups • interact with different targets in the body • different effects

13. Macromolecules • Smaller organic molecules join together to form larger molecules • 4 major classes of macromolecules: • carbohydrates • lipids • proteins • nucleic acids

14. Our Organic Friends! Assessment Statement 3.2.2

15. Carbohydrates Assessment Statement 3.2.3 • Made of C, H and O, where the ratio of C to H to O is 1:2:1. • There are monosaccharides, disaccharides and polysaccharides. • Monosaccharides are the simple sugars. Their molecular formula is C6H12O6. They are single unit sugars. Glucose, fructose and galactose.

17. Identify Glucose Assessment Statement 3.2.2

18. Identify Ribose Assessment Statement 3.2.2

19. Carbohydrates • Most important source of energy – total energy gain is 4 Calories/gram • Carbohydrates are built from sugar molecules (ending in “ose”). • Some famous sugars include: • Glucose (found in human blood -#1 brain food), • Fructose (plant sugar), • deoxyribose (the sugar portion of DNA), • Cellulose (a polysaccharide that makes up plant walls- commonly known as ruffage or fiber). Assessment Statement 3.2.6 Assessment Statement 3.2.3

20. Carbohydrates • Disaccharides are double sugars and are made by combining 2 simple sugars together into a two unit sugar. • Examples are sucrose, maltose and lactose. • Polysaccharides are long chains of repeating sugar units. Multiunit sugar – more than two sugars combined. • Examples are starch, glycogen and cellulose. • Glycogen is stored in animal cells and is often refered to as animal starch. Glycogen is made up of 16 to 24 glucose molecules. The liver converts glycogen into glucose units for energy. Assessment Statement 3.2.3

21. List one function each for: Glucose, lactose, glycogen in animals: • Glucose = monosaccharide, major energy source for fuelling cellular respiration. • Lactose = disaccharide, energy source found in mammalian milk • Glycogen = polysaccharide; energy storage in liver. Assessment Statement 3.2.4

22. List one function each for: Fructose, sucrose and cellulose in plants: • Fructose = monosaccharide: energy component in flower nectar • Sucrose = disaccharide: energy molecule transported via phloem • Cellulose = polysaccharide: major structural component of plant cell walls. Assessment Statement 3.2.4

23. LIPIDS • Commonly known as “fat” – total energy gain 9 Calories/gram. • Foods – fish, olive oil, red meat, nuts. • Are a key component in cells, especially in the cell membrane. • They are made of C, H and O. • Yield twice as much energy as carbohydrates. • Lipids are made up of fatty acids and glycerol. • 2 types of lipids: saturated and unsaturated. Assessment Statement 3.2.6 Assessment Statement 3.2.6

24. LIPIDS • Structure: Lipids are made up of two portions a glycerol head and fatty acid tails. glycerol fatty acids

25. LIPIDS • Lipids can also go through condensation and hydrolsis, just like carbohydrates and proteins.

26. LIPIDS • 3 functions of lipids: • Energy Storage: lipids provide concentrated long-term energy storage which can release fuel for cellular respiration as needed. • Cell membrane: the main component of cell membraes are phospholipids • Thermal insulators: reduce the loss of heat from an organism (e.g. an under the skin layer of lipids). Assessment Statement 3.2.6

27. LIPIDS • When an unsaturated fat has only one unsaturated bond, it is known as monounsaturated. When a fat has more than one unsaturated bond it is known as polyunsaturated. Assessment Statement 3.2.6

28. LIPIDS • Phospholipids and triglycerides and waxes are three important groups of lipids. • Phospholipids are the building blocks of the fluid mosaic model of the cell membrane. They have a phosphate/glycerol head that is polar and hydrophillic and two fatty acid tails that are hydrophobic. • Triglycerides – are another type of lipid found in the body. These special lipid molecules are built from one glycerol and three fatty acids with the help of an enzyme.

29. Saturated Fats • Lipids that are solid or semi-solid at room temperature are said to be saturated (loaded up with covalent bonds to H atoms). • E.g. Butter, shortening and marbling in meat. • Saturated fats are very stable at room temperature.

30. Unsaturated Fats • Lipids that are liquid at room temperature are said to be unsaturated (containing double bonds, or less H atoms). • E.g. Oil is an example of an unsaturated fat. • Unsaturated fats are easier to break down in the body than saturated fats. Hense the push for people to use vegetable or canola oil rather than butter while cooking.

31. Lipid Groups • Waxes – are the third group of lipids. They are formed from long chains of fatty acids joining long-chain alcohol or carbon rings. Waxes are insoluble in water, and are used for water proofing plant leaves or animal feathers and fur. • Fats & Diet – stable fats in the body (saturated fats) tend to stay put once ingested leading to plaque in the arteries and ultimately to health complications (e.g. stroke, cancer, high blood pressure, type two diabetes). • Cholesterol – not all fat is bad. Cholesterol is required by the cell membrane and is also important for the production of hormones (specifically sex hormones – estrogen and testosterone). There are two different types of cholesterol in the blood HDL and LDL. HDL is the “good” cholesterol and LDL is the “bad” cholesterol.

32. PROTEINS • Proteins are made of C, H, O and N. They are the most abundant organic compound found in living cells. • The most important macromolecule in the body. Their importance can not be underestimated! They form: • The structural parts nails, hair, cell membrane and cartilage • Pigments (skin, eyes and chlorophyll), • Hormones • Contractile material of muscle tissues • Antibodies • Enzymes.

33. PROTEINS • The building blocks of proteins are amino acids. • The amino acids are bonded together by peptide bonds to form proteins. • The smallest protein consists of 50 amino acids bonded together and the largest consists of over 100, 000.

34. PROTEINS • Proteins Rule Everything in the Body! • Total energy gain is 4 Calories/gram. (however, energy gain is not their main function). • Your body requries 22 essential amino acids, but can only produce 8! • We must rely on digestion to gain the other amino acids we need. • 22 different amino acid groups give rise to an infinite amount of proteins.

35. PROTEINS • Proteins are large molecules constructed of many amino acids. • Again, condensation and hydrolysis apply to this macronutrient. • The bond that is formed from an acid group (COOH) and the amino group (NH2) is called a peptide bond. Because of this special bond, proteins are frequently called polypeptides (many peptide bonds). Assessment Statement 3.2.5

36. PROTEINS Assessment Statement 3.2.2

37. PROTEINS • Shapes – primary (linear), secondary (coiled), tertiary (bent-coiled) and quarternary (compact with a specific structure). • You can unfold a protein (de-nature) by exposing the protein to heat, radiation or a change in pH. (i.e. frying an egg, baking a cake, UV exposure, x-rays).

38. PROTEINS Assessment Statement 7.5.1

39. Protein Structure Primary protein structure: • Sequence and number of amino acids • Each position occupied by one of 20 amino acids • Linked by peptide bonds Assessment Statement 7.5.1

40. Assessment Statement 7.5.1 Protein Structure Secondary protein structure: • Weak hydrogen bonds between amino and carboxyl groups. • Form at regular intervals, creating a regular structure (not from the interactions between variable R groups) • Alpha helix = coiling into a helix • Beta pleating = a folded sheet as polypeptide folds back onto itself. • Not all of a polypeptide forms secondary structure in most proteins.

41. Assessment Statement 7.5.1 Protein Structure Tertiary protein structure: • Interactions between variable R-groups forming • Hydrophobic interactions between non-polar amino acids • Hydrogen bonds between polar amino acids • Ionic bonds between ionic amino acids • Covalent bonds between sulfur containing amino acids • Producing the three dimensional folded structure of most proteins.

42. Assessment Statement 7.5.1 Protein Structure Quarternary protein structure: • Aggregations of polypeptides form interactions between more than 1 polypeptide • Polypeptides + non-proteinaceous molecules, such as: • Metals, e.g. iron in hemoglobin • Vitamins as enzyme co-factors • Nucleic acids as in ribosomes • Carbohydrates in glycoproteins • Lipids in lipoproteins. http://www.youtube.com/watch?v=lijQ3a8yUYQ

43. Outline the difference between fibrous and globular proteins, with reference to two examples of each type of protein. • Fibrous: • Long fibers or sheets formed by parallel polypeptide chains • Dominated mostly by secondary structure • Mostly water insoluble • Great strength and/or strechiness from affects of regular H-bonds • Collagen in connective tissue • Actin and myosin in muscle tissue Assessment Statement 7.5.2

44. Outline the difference between fibrous and globular proteins, with reference to two examples of each type of protein. • Globular: • Folded into complex 3D irregular spherical shape • Dominated mostly by tertiary structure • Mostly water soluble • Functions determined by 3D shape • Enzymes such as amylase • Hormones such as insulin • Transport such as hemoglobin • Protective, such as immunoglobulins Assessment Statement 7.5.2

45. Explain the significance of polar and non-polar amino acids • Amino acids fit into three groups: • Polar • Ionic • Non-polar Assessment Statement 7.5.3

46. Ionic and Polar amino acids • Have hydrophillic R groups • Attracting the protein to water • Forming H bonds and ionic bonds between different amino acid R groups • Contributing to tertiary structure Assessment Statement 7.5.3

47. Non-polar amino acids • Have hydrophobic R groups • Repelling the protein from water • Forming hydrophobic bonds between different amino acid R groups • Contributing to tertiary structure • Contributing to protein attraction to fatty acids in the phospholipid bilayer Assessment Statement 7.5.3

48. Polar and Non-polar Amino Acids: • The distribution of polar and non-polar amino acids in a protein determine where in a membrane or cell a protein will be located and the function it will perform. Assessment Statement 7.5.3

49. State four functions of proteins, giving a named example of each. Assessment Statement 7.5.4

50. Metabolism • All the chemical reactions that occur in your body. Approximately 200, 000 chemical reactions occur daily within one single cell. • Catabolic and anabolic reactions are two types of reactions that occur inside the cells. • Catabollic reactions occur when large chemicals are broken down into smaller components. • Anabollic reactions, complex chemicals are built from smaller components.