Chapter 4b Carbon Compounds In Cells

Organic Compounds Hydrogen and other elements covalently bonded to carbon Carbohydrates Lipids Proteins Nucleic Acids `

Carbon’s Bonding Behavior 1) Outer shell of carbon has 4 electrons; can hold 8 2) Each carbon atom can form covalent bonds with up to four atoms`

Structural Representations

Bonding Arrangements 1) Carbon atoms can form chains or rings 2) Other atoms project from the carbon backbone`

Functional Groups 1) Atoms or clusters of atoms that are covalently bonded to carbon backbone –a) Give organic compounds their different properties`

Examples of Functional Groups Hydroxyl group - OH Amino group- NH 3 + Carboxyl group- COOH Phosphate group- PO 3 - Sulfhydryl group- SH`

Functional Groups

Carbohydrates Monosaccharides (simple sugars) Oligosaccharides (short-chain carbohydrates) Polysaccharides (complex carbohydrates) `

Monosaccharides 1) Simplest carbohydrates 2) Most are sweet tasting, water soluble 3) Most have 5- or 6-carbon backbone Glucose (6 C)Fructose (6 C) Ribose (5 C)Deoxyribose (5 C)`

Two Monosaccharides glucosefructose

Monosaccharide

Disaccharides 1) Type of oligosaccharide 2) Two monosaccharides covalently bonded 3) Formed by condensation reaction` + H 2 O glucosefructose sucrose

Sucrose Formation

Polysaccharides 1) Straight or branched chains of many sugar monomers 2) Most common are composed entirely of glucose –a) Cellulose –b) Starch (such as amylose) –c) Glycogen`

Cellulose & Starch 1) Differ in bonding patterns between monomers –a) Cellulose - tough, indigestible, structural material in plants –b) Starch - easily digested, storage form in plants`

Cellulose and Starch

Starch Cellulose

Glycogen 1) Sugar storage form in animals –a) Large stores in muscle and liver cells 1. When blood sugar decreases, liver cells degrade glycogen, release glucose`

Chitin 1) Polysaccharide –a) Nitrogen-containing groups attached to glucose monomers –b) Structural material for hard parts of invertebrates, cell walls of many fungi`

1) Most include fatty acids –a) Fats –b) Phospholipids –c) Waxes 2) Sterols and their derivatives have no fatty acids –a) Tend to be insoluble in water` Lipids

Fatty Acids 1) Carboxyl group (-COOH) at one end 2) Carbon backbone (up to 36 C atoms) –a) Saturated - Single bonds between carbons –b) Unsaturated - One or more double bonds`

Three Fatty Acids

Fats 1) Fatty acid(s) attached to glycerol –a) Triglycerides are most common`

Triglyceride

Phospholipids 1) Main components of cell membranes`

Phospholipid

Sterols and Derivatives 1) No fatty acids 2) Rigid backbone of four fused-together carbon rings 3) Cholesterol - most common type in animals`

Cholesterol

Waxes 1) Long-chain fatty acids linked to long chain alcohols or carbon rings –a) Firm consistency, repel water –b) Important in water-proofing`

Amino Acid Structure amino group carboxyl group R group

Properties of Amino Acids 1) Determined by the “R group” 2) Amino acids may be: –a) Non-polar –b) Uncharged, polar –c) Positively charged, polar –d) Negatively charged, polar`

Amino Acids

Protein Synthesis 1) Protein is a chain of amino acids linked by peptide bonds –a) Peptide bond 1. Type of covalent bond 2. Links amino group of one amino acid with carboxyl group of next 3. Forms through condensation reaction`

Peptide Bond

Primary Structure 1) Sequence of amino acids 2) Unique for each protein 3) Two linked amino acids = dipeptide 4) Three or more = polypeptide 5) Backbone of polypeptide has N atoms: -N-C-C-N-C-C-N-C-C-N-`

A Permanent Wave hair wrapped around cuticles different bridges form bridges broken

Primary Structure

Secondary/Tertiary

Quaternary

Studying Spider Silk

Enzyme Structure and Function 1) Enzymes are catalytic molecules a) They speed the rate at which reactions approach equilibrium`

Four Features of Enzymes 1) Enzymes do not make anything happen that could not happen on its own. They just make it happen much faster 2) Reactions do not alter or use up enzyme molecules`

Four Features of Enzymes 3) The same enzyme usually works for both the forward and reverse reactions 4) Each type of enzyme recognizes and binds to only certain substrates`

1) Sugar –a) Ribose or deoxyribose 2) At least one phosphate group 3) Base –a) Nitrogen-containing –b) Single or double ring structure` Nucleotide Structure

Nucleotide Functions Energy carriers Coenzymes Chemical messengers Building blocks for nucleic acids`

ATP - A Nucleotide three phosphate groups sugar base

ATP

1) Composed of nucleotides 2) Single- or double-stranded 3) Sugar-phosphate backbone` Nucleic Acids Adenine Cytosine

DNA Subunits

DNA 1) Double- stranded 2) Consists of four types of nucleotides –a) A bound to T –b) C bound to G`

DNA Structure

RNA 1) Usually single strands 2) Four types of nucleotides –a) Unlike DNA, contains the base uracil in place of thymine 3) Three types are key players in protein synthesis`

DNA/RNA