Biological organization 1. Biological molecules 2. Cellular organization

Important biological molecules Small molecules Polymers/macromolecules

Small molecules 1.Carbohydrates/sugars Source of energy Structural component Component of nucleic acids Protein modifier

Small molecules Nitrogenous Base Five carbon sugar Phosphate backbone 2. Nucleotides

Small molecules 2.Nucleotides Component of nucleic acids (genetic information) Energy storage (ATP/GTP/etc.) Facilitate reaction catalysis (eg. coenzyme A)

Small molecules 3.Amino acids Components of proteins Source of energy Intercellular communication etc.

Small molecules 3.Amino acids 20 “common” amino acids Carboxylic acid, amino group, ‘R’-group Alpha carbon (in most amino acids) is a stereocenter: L for life

Small molecules 1.Carbohydrates 2.Nucleotides 3.Amino acids 4.(Water)

Macromolecules 1.Nucleic acids Polymers of nucleotides Genetic information encoded in the sequence of bases

Nitrogenous Base Five carbon sugar Phosphate backbone

Nucleotides polymerize via phosphodiester bonds

Macromolecules 2.Lipids Source of energy Form protective cell membrane Intra- and inter-molecular communication

Macromolecules 3.Proteins Polymers of amino acids Source of energy Structural components Enzymes etc.

Macromolecules 1.Nucleic acids (polymers of nucleotides) 2.Lipids 3.Protein (polymers of amino acids)

The cell Maintain/transfer genetic material Produce macromolecules Protect itself Take in nutrients Harvest energy

Eukaryotic cells contain “organelles” Functions are compartmentalized within the cytoplasm Nucleus ER/Golgi Cell membrane Mitochondria

Nucleus: Maintain & Transfer Genetic Information DNA –Copy –‘Read’: Transcription → Make RNA RNA → protein = “Translation” –Proofread: check/repair damage Define cellular characteristics

Information is carried in the base purines pyrimidines “CUT one piece of ‘py’”

Produce macromolecule Endoplasmic reticulum/Golgi: Ribosomes –Structures that assemble proteins from amino acids –Proteins on rough ER Smooth ER: lipid synthesis Golgi –Further protein processing, sugar incorporation

Ribosomes Huge multi-component structures –Millions of daltons –Protein and nucleic acid components –Considered an ‘organelle’

Cell protection Plasma membrane Lipid bilayer, proteins, carbohydrates, etc.

Cell membrane: lipid bilayer

Energy harvest: mitochondria Citric acid cycle (oxidation of pyruvate) Electron transport (generation of a proton gradient) ATP synthesis