Biology STAAR review Session 2 Biomolecules and Enzymes

9 A. You need to know the significance of various molecules involved in metabolic processes and energy conversions that occur in living organisms. • You are expected to compare the structures and functions of different types of biomolecules, including carbohydrates, lipids, proteins, and nucleic acids. v Large organic molecules are created by the process of POLYMERIZATION. v Mono=1 v Poly=many

Carbohydrates Starch Glucose • Composed of C, H, O • Monomer – monosaccharides (sugars) • Structure/shape – hexagon • Function - main source of energy, support cells • Examples – Glucose, fructose - mono – Cellulose, glycogen, starch - poly • Found in – fruits & veggies

Lipids • Composed of C H O • Structure/shape – E • Monomer – One glycerol & 3 fatty acids • Function– Stores long-term energy – Main component of cell membrane – Waterproof covering • Examples - Fats, oils, mono & polyunsaturated • Found in – butter, animal fats, oils

Protein • • Composed of C H O N Structure/shape Monomer – amino acids Function – Build cells & body structures – Transports molecules in cell membranes • Examples – – found in muscles, bone, skin, hair, – Enzymes, hormones Amino acids

Nucleic Acid • Composed of CHONP • Monomer – nucleotides • Structure/shape • Function – Store & transmit genetic info – Instruction for protein synthesis • Examples – DNA, RNA

Monomers that make up Polymers Aka carbohydrates

9 C. You are expected to identify and investigate the role of enzymes • Enzymes control the rate of chemical reactions by weakening bonds, thus lowering the amount of activation energy needed • Specialized proteins, catalysts (speed up chemical reactions), build and break down • Do NOT change during reaction, are reusable, • Are specific to reaction & end in “ -ase” Example: Lactase speeds up the breakdown of lactose

Factors that affect enzymes • Environmental conditions – Temperature, p. H, Salt • Inhibitors – Chemicals interfere with active site • Coenzymes/cofactors – Ex. Zinc, iron, vitamins – Needed for enzymes to bind properly to substrates

9 D. You are expected to analyze and evaluate the evidence regarding the formation of simple organic molecules and their organization into long complex molecules having information such as the DNA molecule for self replicating life.

The diagram represents one way an enzyme can be inhibited. Which statement explains the effect of an inhibitor on an enzyme? A. A substrate will be able to bond with the enzyme. B. The enzyme will likely be attacked by immune cells. C. The enzyme will be unable to produce more enzymes. D. A substrate will be unable to attach to the enzyme.

D

Four different nucleotides are used as building blocks of DNA. Which of the following can be used to distinguish one nucleotide from another? F. The nitrogenous base G. The shape of the deoxyribose sugar H. The length of the phosphate group J. The type of fatty acid

F

The complex carbohydrates pictured below are made by linking molecules of glucose. In all three complex carbohydrates, the subunits of glucose are bonded together differently. Because they have different structures, they most likely — A. contain different chemical elements B. form different proteins C. carry different nucleotides D. perform different functions

D