The Molecules of Cells Chapter Three

Inorganic Compounds Life’s molecular diversity is based on the properties of carbon

Organic Compounds

Polymers Cells make large polymers from joining together small molecules/building blocks called monomers Monomers are linked together by covalent bonds So, a polymer is a chain-like molecule consisting of many similar/identical monomers

Cells Make and Break Polymers Using Two Main Types of Chemical Reactions Dehydration (synthesis) reactions: are used to link monomers together to form polymers; a molecule of water is lost in the reaction Each monomer contributes part of the H2O molecule that is lost

Cells Make and Break Polymers Using Two Main Types of Chemical Reactions Hydrolysis reactions: are used to break polymers into monomers; the bond is broken using water reverse of the dehydration synthesis reactions

Type of chemical reaction? Two events happening in this reaction? 3. Type of chemical reaction? 4. Two events happening in this reaction?

Carbohydrates Three classes Contain C, H, and O Polymers of monosaccharides Provide cellular fuel & give structure to RNA and DNA Three classes Monosaccharides Ex. Glucose Disaccharides Ex’s., fructose, sucrose, maltose Polysaccharides Ex’s. starch, glycogen, cellulose

Carbohydrates: Polysaccharides

Lipids Contain C, H, O, sometimes P Mainly insoluble in water Several Classes of Lipids Triglycerides Phospholipids Steroids

Triglycerides Triglycerides are solid fats and liquid oils 3 fatty acids bound to 1 glycerol (3:1) Functions Energy storage Insulation Protection

Phospholipids Similar to triglycerides 2 fatty acids bound to 1 glycerol (2:1), bound to a phosphate group Polar “head” and non-polar “tail” Phospholipids are the main component of cellular membranes

Steroids Composed of four fused carbon rings Ex’s. Cholesterol, vitamin D, steroid hormones, and bile salts

Proteins Contain C, H, O, N, sometimes S Polymers of amino acids All 20 amino acids have same basic structure Amino acids are held together by peptide bonds (polypeptides)

Denaturing Natural Folding https://www.youtube.com/watch?v=yZ2aY5lxEGE (protein folding animation 2m 19 s) start around 1:11

Protein Folding

Nucleic Acids Only two examples are DNA and RNA Contain C, O, H, N, and P Polymers of nucleotides: nucleotides have 3 parts: a N-containing base, a pentose sugar, and a phosphate group

Deoxyribonucleic Acid (DNA) Four bases in DNA: adenine (A), guanine (G), cytosine (C), and thymine (T) Double-stranded, helical Replicates before every cell division, ensuring genetic continuity Provides instructions for proteins

Deoxyribonucleic Acid (DNA)

Ribonucleic Acid (RNA) Four bases in RNA: adenine (A), guanine (G), cytosine (C), and uracil (U) Uracil replaces thymine in RNA Single-stranded Mainly active outside of nucleus