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Biochemistry.

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Presentation on theme: "Biochemistry."— Presentation transcript:

1 Biochemistry

2 Carbon Building block of all life
Carbon is the basis for most molecules that make up living things Atomic Number 6 4 valence electrons Can form 4 bonds with 4 different atoms at the same time, including another carbon

3 Bohr Model

4 Lewis Dot Diagram

5 Carbon Structures Straight Branched Rings
Carbon chains bond with carbon rings to form very large and complex molecules

6

7 Organic Chemistry Molecules that contain the element Carbon
All contain C and H, most contain C, H and O

8 The Structure and Function of Macromolecules

9 I. Polymers What is a polymer?
Poly = many; mer = part. A polymer is a large molecule consisting of many smaller sub-units bonded together. What is a monomer? A monomer is a sub-unit of a polymer.

10 A. Making and Breaking Polymers
How are covalent linkages between monomers formed in the creation of organic polymers? Condensation or dehydration synthesis reactions. Monomers are covalently linked to one another through the removal of water.

11 Condensation Synthesis

12

13 Hydrolysis What is a hydrolysis reaction?
Polymers are broken down into monomers. Hydro = water; lysis = loosening/ Water is added and the lysis of the polymer occurs.

14 Hydrolysis

15 II. Classes of Organic Molecules:
What are the four classes of organic molecules? Carbohydrates Lipids Proteins Nucleic Acids

16 A. Carbohydrates Sugars
Carbo = carbon, hydrate = water; carbohydrates have the molecular formula (CH2O)n Functions: Chemical energy Plant cell structure (cellulose)

17 1. Structure of Monosaccharides
An OH group is attached to each carbon except one, which is double bonded to an oxygen (carbonyl).

18 Classified according to the size of their carbon chains, varies from 3 to 7 carbons.
Triose = 3 carbons Pentose = 5 carbons Hexose = 6 carbons

19 In aqueous solutions many monosaccharides form rings:

20 2. Structure of Disaccharides
Double sugar that consists of 2 monosaccharides, joined by a glycosidic linkage. What reaction forms the glycosidic linkage? Condensation synthesis

21 Examples of Disaccharides:
Lactose = glucose + galactose Sucrose = glucose + fructose

22 3. Polysaccharides Structure: Polymers of a few hundred or a few thousand monosaccharides. Functions: energy storage molecules or for structural support:

23 Starch is a plant storage form of energy, easily hydrolyzed to glucose units
Cellulose is a fiber-like structural material - tough and insoluble - used in plant cell walls Glycogen is a highly branched chain used by animals to store energy in muscles and the liver. Chitin is a polysaccharide used as a structural material in arthropod exoskeleton and fungal cell walls.

24 B. Lipids Structure: Greasy or oily nonpolar compounds Functions:
Energy storage membrane structure Protecting against desiccation (drying out). Insulating against cold. Absorbing shocks. Regulating cell activities by hormone actions.

25 1. Structure of Fatty Acids
Long chains of mostly carbon and hydrogen atoms with a -COOH group at one end. When they are part of lipids, the fatty acids resemble long flexible tails.

26 Saturated and Unsaturated Fats
liquid at room temp one or more double bonds between carbons in the fatty acids allows for “kinks” in the tails most plant fats Saturated fats: have only single C-C bonds in fatty acid tails solid at room temp most animal fats

27

28 Saturated fatty acid

29 Unsaturated fatty acid

30 2. Structure of Triglycerides
Glycerol + 3 fatty acids 3 ester linkages are formed between a hydroxyl group of the glycerol and a carboxyl group of the fatty acid.

31 3. Phospholipids Structure: Glycerol + 2 fatty acids + phosphate group. Function: Main structural component of membranes, where they arrange in bilayers.

32 Phospholipids in Water

33 4. Waxes Function: Lipids that serve as coatings for plant parts and as animal coverings.

34 5. Steroids Structure: Four carbon rings with no fatty acid tails
Functions: Component of animal cell membranes Modified to form sex hormones

35 C. Proteins Structure: Polypeptide chains
Consist of peptide bonds between 20 possible amino acid monomers Have a 3 dimensional globular shape

36 1. Functions of Proteins Enzymes which accelerate specific chemical reactions up to 10 billion times faster than they would spontaneously occur. Structural materials, including keratin (the protein found in hair and nails) and collagen (the protein found in connective tissue).

37 Specific binding, such as antibodies that bind specifically to foreign substances to identify them to the body's immune system. Specific carriers, including membrane transport proteins that move substances across cell membranes, and blood proteins, such as hemoglobin, that carry oxygen, iron, and other substances through the body.

38 Contraction, such as actin and myosin fibers that interact in muscle tissue.
Signaling, including hormones such as insulin that regulate sugar levels in blood.

39 2. Structure of Amino Acid Monomers
Consist of an asymmetric carbon covalently bonded to: Hydrogen Amino group Carboxyl (acid) group Variable R group specific to each amino acid

40 Properties of Amino Acids
Grouped by polarity Variable R groups (side chains) confer different properties to each amino acid: polar, water soluble. non-polar, water insoluble positively charged negatively charged.

41 4 levels of protein structure:
primary secondary tertiary quaternary

42 3. Primary Structure Unique sequence of amino acids in a protein
Slight change in primary structure can alter function Determined by genes Condensation synthesis reactions form the peptide bonds between amino acids

43

44 4. Secondary Structure Repeated folding of protein’s polypeptide backbone stabilized by H bonds between peptide linkages in the protein’s backbone 2 types, alpha helix, beta pleated sheets

45

46 5. Tertiary Structure Irregular contortions of a protein due to bonding between R groups Weak bonds: H bonding between polar side chains ionic bonding between charged side chains hydrophobic and van der Waals interactions Strong bonds: disulfide bridges form strong covalent linkages

47

48 5. Quaternary Structure Results from interactions among 2 or more polypeptides

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50 Factors That Determine Protein Conformation
Occurs during protein synthesis within cell Depends on physical conditions of environment pH, temperature, salinity, etc. Change in environment may lead to denaturation of protein Denatured protein is biologically inactive Can renature if primary structure is not lost

51 D. Nucleic Acids Two kinds: DNA: RNA: double stranded
can self replicate makes up genes which code for proteins is passed from one generation to another RNA: single stranded functions in actual synthesis of proteins coded for by DNA is made from the DNA template molecule

52

53 1. Nucleotide Monomer Structure
Both DNA and RNA are composed of nucleotide monomers. Nucleotide = 5 carbon sugar, phosphate, and nitrogenous base Deoxyribose in DNA Ribose in RNA

54

55 2. Building the Polymer Phosphate group of one nucleotide forms strong covalent bond with the #3 carbon of the sugar of the other nucleotide.

56 3. Functions of Nucleotides
Monomers for Nucleic Acids Transfer chemical energy from one molecule to another (e.g. ATP)

57 DNA: Double helix 2 polynucleotide chains wound into the double helix Base pairing between chains with H bonds A - T C - G

58 Summary of the Organic Molecules:


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