Biochemistry Chapter 3

Chapter 3 Vocabulary Monomer Disaccharide Polymer Polysaccharide Condensation reaction Protein Hydrolysis Amino acid Adenosine triphosphate Substrate Fatty acid Carbohydrate Triglyceride Monosaccharide Steroid

Carbon Compounds Two broad categories of compounds Organic Inorganic Organic compounds – made primarily of carbon atoms Most matter in living organisms is made up of organic compounds

Functional Groups Functional groups - is the portion of an organic molecule that is active in a chemical reaction and that determines the molecule's properties.  Clusters of atoms Influence the characteristics of molecules

Functional Groups

Large Carbon Molecules Monomers – small, simple molecules Polymers – monomers bonded to one another to form repeated, linked units Macromolecules – large polymers

Formation of Large Carbon Molecules Condensation reaction – when monomers link to form polymers, resulting in the release of a water molecule Hydrolysis – when water is used to break down a polymer. The reverse of a condensation reaction.

Energy Currency Life’s processes require a constant supply of energy. Energy is available in certain compounds ATP (adenosine triphosphate) is an important energy supplier ATP used by the cell to drive the chemical reactions that allow the cell to function.

Macromolecules You are responsible for explaining the type of macromolecule to the class Carbohydrates Lipids Nucleic Acids Proteins

Self Quiz How do carbon molecules form? How do they break down? What are the 4 functional groups we discussed in class? What do they look like? What is ATP?

Molecules of Life

Carbohydrates Carbohydrates – organic compounds composed of carbon, hydrogen, and oxygen. Ratio 1:2:1 (C:H:O) Source of energy Structural materials

Carbohydrates Three types: Monosaccharides Disaccharides Polysaccharides

Monosaccharides Simple sugar Contains carbon, hydrogen, and oxygen General formula (CH2O)n Most common are: Glucose Fructose Galactose Have same chemical formula but different structures, known as isomers

Disaccharides and Polysaccharides Disaccharide – a double sugar Fructose + glucose = sucrose Polysaccharide – a complex molecule of three or more monosaccharides Glycogen – the form of glucose that animals store Starch – the form of glucose that plants store Cellulose – a large polysaccharide that gives plant cells strength and rigidity.

Proteins Proteins – organic compounds composed mainly of carbon, hydrogen, oxygen, and nitrogen. Formed from monomers called amino acids

Amino Acids 20 different amino acids (a.a.) Share a basic structure Central carbon 4 functional groups

Dipeptides and Polypeptides Dipeptide – two amino acids bonded Peptide bond – formed by a condensation reaction. Two amino acids form a covalent bond. Polypeptide – long chains of amino acids

Enzymes Enzymes – RNA or protein molecules that act as biological catalysts Are essential for the functioning of the cell Many enzymes are proteins

Enzyme Reactions Depend on physical fit between enzyme and substrate Substrate – the reactant being catalyzed Active site – where the substrate fits on the enzyme Enzymes are substrate specific Link of enzyme and substrate causes slight change in enzyme shape

Lipids Lipids – large, nonpolar organic molecules Lipids do not dissolve in water Types of lipids: Triglycerides Phospholipids Steroids Waxes Pigments

Fatty Acids Fatty acid – unbranched hydrocarbon chains that make up most lipids Hydrophilic and hydrophobic ends Saturated and unsaturated Saturated – only single bonds, carbons full Unsaturated – double bonds, carbons not full

Triglycerides Triglyceride – composed of three molecules of fatty acid joined to one molecule of glycerol Saturated Ex. butter Unsaturated Ex. Plant seeds

Phospholipids Phospholipids – have two fatty acid chains attached to glycerol and a phosphate group attached to the glycerol. Phospholipid bilayer – makes up the cell membrane

Waxes and Steroids Wax – a type of structural lipid A long fatty acid chain joined to a long alcohol chain. Waterproof, protective coating Steroids – composed of four fused carbon rings with various functional groups Cholesterol is an important one

Nucleic Acids Nucleic acids – very large and complex organic molecules that store and transfer information in the cell Two major types DNA – deoxyribonucleic acid RNA – ribonucleic acid

DNA and RNA DNA contains information that determines the characteristics of an organism RNA stores and transfers information from DNA. Some RNA molecules can act as enzymes DNA and RNA are polymers composed of nucleotides Nucleotide Phosphate group Five-carbon sugar Nitrogenous base

Self Quiz What are the three components of a nucleotide? How many amino acids are there? What are the three types of carbohydrates? What does it mean that enzymes are substrate specific? What are the two main types of nucleic acids?