Molecules of Life

Hydrogen and other elements covalently bonded to carbon Organic Compounds Hydrogen and other elements covalently bonded to carbon Four types of organic compounds: Carbohydrates Lipids Proteins Nucleic Acids

What’s so special about Carbon? Carbon wants to make 4 bonds with other elements which leads to a big molecule ***Remember Carbon has 4 valence electrons***

What’s so special about Carbon? Straight Branched Ringed

What’s so special about Carbon? Single bonds Double bonds Triple bonds With other carbons or other elements C-C-C-C C=C=C

Carbohydrates Elements: C H2 O Basic building blocks or MONOMERS: Monosaccharides (simple sugars) Ex: Glucose, Fructose DIMERS or Disaccharides: Ex Sucrose, Maltose Function: Energy

Functional Groups Since most organic compounds are large molecules, the entire molecule does not take part in the chemical reaction Only a few atoms that are covalently bonded will take part in the chemical reaction These are called functional groups (groups of atoms that function in the molecule) Give organic compounds their different properties

Examples of Functional Groups Hydroxyl group - OH Amino group - NH3+ Carboxyl group - COOH Phosphate group - PO3- Sulfhydryl group - SH

Types of Reactions Two main types of reaction happen in a cell Condensation/dehydration synthesis = small molecules or monomers are joined together or condensed to make a larger molecule Cleavage or hydrolysis = large molecules or polymers are broken down or cleaved to form smaller molecules

Condensation

Hydrolysis A type of cleavage reaction Breaks polymers into smaller units An -OH group and an H atom derived from water are attached at exposed sites

Hydrolysis

Carbohydrates POLYMERS: Oligosaccharides (short-chain carbohydrates) And Polysaccharides (long chain or complex carbohydrates)

Cellulose and Starch Cell walls component Stores of carbs in potato

Glycogen Sugar storage form in animals Large stores in muscle and liver cells When blood sugar decreases, liver cells degrade glycogen, release glucose

What is the function of carbs? Energy Support Energy storage All of the above A and B only

What is the function of carbs? Energy Support Energy storage All of the above A and B only

Which of these are monomers of carbs? Starch Glycogen Glucose Cellulose

Which of these are monomers of carbs? Starch Glycogen Glucose Cellulose

Common Characteristics of Carbohydrates Hydrophilic- many hydroxyl groups (OH) 2) Mono and disaccharides dissolve in water = sugar solution 3) Cellulose and some starch do not dissolve in water because they are too big

Lipids Elements C, H, O Monomers are Fatty acids Glycerol Polymers are Fats Phospholipids Waxes

Fats Glycerol Function: Energy stores Thermal Insulation Fatty Acid Fatty acid(s) attached to glycerol makes Triglycerides Glycerol Function: Energy stores Thermal Insulation Fatty Acid

Fatty Acids Carboxyl group (COOH) at one end Carbon backbone (up to 36 C atoms) Saturated (bad fat)- Single bonds between carbons Unsaturated (good fat)- One or more double bonds

Phospholipids Main components of cell membranes

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

Steroids No fatty acids Rigid backbone of four fused-together carbon rings Cholesterol - most common type in animals Estrogen, testosterone

Give two differences and two similarities between a carb and a lipid?

Give two differences and two similarities between a carb and a lipid? Lipids and carbs have CHO Lipids and carbs provide energy to the cell Both have OH functional group Carbs have CH2O, Lipids have no ratio Lipids are long term, carbs are short term Lipids have OH and COOH functional group, carbs have OH Hormones are lipids

Proteins Elements C, H, O, N, sometimes S Monomers: Amino acids Polymers: Polypeptides or proteins Examples: hair, muscle.

20 types of R groups = 20 types of amino acids carboxyl group amino group R group 20 types of R groups = 20 types of amino acids

Polymer = two or more monomers joined by - Covalent bonds Specifically peptide bonds What is a dipeptide? Polypeptide?

Protein have Shapes Fibrous proteins Globular proteins Polypeptide chains arranged as strands or sheets Globular proteins Polypeptide chains folded into compact, rounded shapes

Primary Structure Sequence of amino acids Unique for each protein one peptide group

Secondary Structure Hydrogen bonds form between different parts of polypeptide chain These bonds give rise to coiled or extended pattern Helix or pleated sheet

Tertiary Structure heme group Folding as a result of interactions between R groups coiled and twisted polypeptide chain of one globin molecule

Quaternary Structure Some proteins are made up of more than one polypeptide chain Hemoglobin

Functions of Proteins Enzymes which control and speed up all chemical reactions in our bodies Hormones which act as signals to tell the body what to do and when Antibodies help our bodies fight infection 5. Hemoglobin carries oxygen around our bodies

Functions of Proteins 6. Storage – in Milk, eggs, seeds etc 7. Structure of cell and body – web, silk, hair, skin, feathers Motor – muscle proteins, cilia, flagella Receptor proteins – recieves signals from nerves that help in response to stimuli

Important protein: Enzyme Structure and Function Protein that coordinates all cell activity Enzymes are catalytic molecules They speed the rate of reactions IMPORTANT: All enzymes are protein BUT all proteins are not enzymes

Process of enzyme activity

How enzymes work Substrate ( reactant) fits into the active site of the enzyme The enzyme breaks/forms bonds and releases the products The enzyme can then be used again with another substrate

Four Features of Enzymes Enzymes do not make anything happen that could not happen on its own. They just make it happen much faster. Reactions do not alter or use up enzyme molecules. The same enzyme usually works for both the forward and reverse reactions. Each type of enzyme recognizes and binds to only certain substrates.

Activation Energy For a reaction to occur, an energy barrier must be surmounted Enzymes make the energy barrier smaller activation energy without enzyme starting substance activation energy with enzyme energy released by the reaction products

Factors Influencing Enzyme Activity Temperature pH Salt concentration Enzymes secondary, tertiary and quaternary structures change but the primary structure does not – why?