Biology I Basic Chemistry & Biochemistry: The Chemical Basis of Life

Part I: Basic Chemistry: Key Words and Concepts Element Element Atom Atom Compounds Compounds Molecule Molecule Ions Ions Acid and Base Acid and Base pH pH Diffusion and Osmosis Diffusion and Osmosis

Review: Basic Chemistry Matter Matter anything that has a mass and takes up a space anything that has a mass and takes up a space all matter is composed of elements all matter is composed of elements Element Element is a substance that can not be broken down into simpler substances. Example: oxygen (O), hydrogen (H), carbon (C) is a substance that can not be broken down into simpler substances. Example: oxygen (O), hydrogen (H), carbon (C) Each element has a set of properties that distinguish it from from other elements. Example: copper is a bronze colored solid that conducts heat; oxygen is odorless/colorless at room temperature. Each element has a set of properties that distinguish it from from other elements. Example: copper is a bronze colored solid that conducts heat; oxygen is odorless/colorless at room temperature.

Review: Basic Chemistry Atom Atom is the smallest particle of an element that retains the characteristics of that element is the smallest particle of an element that retains the characteristics of that element Example: all atoms of copper have the properties of copperExample: all atoms of copper have the properties of copper The center of each atom contains a nucleus composed of 2 different particles: protons (+ charge) and neutrons (with no charge) The center of each atom contains a nucleus composed of 2 different particles: protons (+ charge) and neutrons (with no charge) Moving in regions outside the nucleus is a particle called the electron (- charge) Moving in regions outside the nucleus is a particle called the electron (- charge)

Structure of an Atom

Review: Basic Chemistry Atom Atom Every atom in an element has an equal number of protons and electrons, and is electrically balanced, or neutral Every atom in an element has an equal number of protons and electrons, and is electrically balanced, or neutral Every atom has energy, or the ability to do work Every atom has energy, or the ability to do work This energy (called chemical energy), comes from electrons in the atom This energy (called chemical energy), comes from electrons in the atom

Review: Basic Chemistry Compounds Compounds Substances made from elements are compounds. A chemical formula shows the kinds and proportions of atoms in a compound. Ex: NaCl stands for sodium chloride (salt) from sodium (Na) and chlorine (Cl) Substances made from elements are compounds. A chemical formula shows the kinds and proportions of atoms in a compound. Ex: NaCl stands for sodium chloride (salt) from sodium (Na) and chlorine (Cl) Molecules Molecules Are the smallest units of a compound that still have the properties of that compound. (in H 2 O, the ratio of H and O is 2:1, so the formula is H 2 O) Are the smallest units of a compound that still have the properties of that compound. (in H 2 O, the ratio of H and O is 2:1, so the formula is H 2 O) Ions Ions Electrically charged (+/-) molecules are called IONS Electrically charged (+/-) molecules are called IONS

Review: Basic Chemistry Acids and Bases Acids and Bases Two common groups of compounds that react in water are ACIDS and BASES Two common groups of compounds that react in water are ACIDS and BASES Acid is a substance that releases hydrogen ions (protons) when mixed with water (proton donor) Acid is a substance that releases hydrogen ions (protons) when mixed with water (proton donor) Example: CH 3 COOH --–H 2 0– H + + CH 3 COO – Example: CH 3 COOH --–H 2 0– H + + CH 3 COO – Base is a substance that separates in water, forming ions that react with hydrogen ions (proton acceptor) Base is a substance that separates in water, forming ions that react with hydrogen ions (proton acceptor) Example: NaOH + CH 3 COOH --– H CH 3 COONa Example: NaOH + CH 3 COOH --– H CH 3 COONa

Review: Basic Chemistry pH pH The strength of an acid or base is measured by the pH scale (0-14, 7 being neutral: water) The strength of an acid or base is measured by the pH scale (0-14, 7 being neutral: water) pH of acid solution: 0-7; of basic solution 7-14 pH of acid solution: 0-7; of basic solution 7-14 The pH scale is based on powers of 10. Thus Cola with a pH of 3 is 10 times more acidic than Tomato juice with a pH of 4 The pH scale is based on powers of 10. Thus Cola with a pH of 3 is 10 times more acidic than Tomato juice with a pH of 4 Living cells are very sensitive to pH of their environment. Our cells are in a pH of 7.2. If the pH changes by only 2/10 th of a point, cells die Living cells are very sensitive to pH of their environment. Our cells are in a pH of 7.2. If the pH changes by only 2/10 th of a point, cells die

Review: Basic Chemistry Diffusion & Osmosis Diffusion & Osmosis Diffusion : movement of a molecule/substance from a higher to a lower concentration Diffusion : movement of a molecule/substance from a higher to a lower concentration Osmosis : movement of water molecules through a semi-permeable membrane from a higher to a lower water concentration Osmosis : movement of water molecules through a semi-permeable membrane from a higher to a lower water concentration

Biochemistry

What is Biochemistry? Biochemistry is the study of the chemical interactions of living things.Biochemistry is the study of the chemical interactions of living things. Biochemists study the structures and physical properties of biological molecules.Biochemists study the structures and physical properties of biological molecules. Often are involved in the manufacture of new drugs and medical treatmentsOften are involved in the manufacture of new drugs and medical treatments

Elements in Living Organisms The most common elements found in living organisms include:The most common elements found in living organisms include: Carbon (C) Oxygen (O) Nitrogen (N) Hydrogen (H) Phosphorus (P) Sulfur (S)

Periodic Table of the Elements (excerpt)

Biochemistry: Where Chemistry & Biology Meet Living things require millions of chemical reactions just to survive.Living things require millions of chemical reactions just to survive. Metabolism = all the chemical reactions occurring in the body.Metabolism = all the chemical reactions occurring in the body. Organic molecules:Organic molecules: usually associated with living things.usually associated with living things. always contain CARBON.always contain CARBON. are “large” molecules, with many atomsare “large” molecules, with many atoms always have covalent bonds (share electrons)always have covalent bonds (share electrons)

Macromolecules of Cells Macro = largeMacro = large 4 types of macromolecules4 types of macromolecules 1. Carbohydrates 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic Acids

Macromolecule #1: Carbohydrates Sugars and groups of sugarsSugars and groups of sugars Purposes: energy and structurePurposes: energy and structure Includes three types:Includes three types: Monosaccharide (1 sugar – quick energy)Monosaccharide (1 sugar – quick energy) Disaccharide (2 sugars – short storage)Disaccharide (2 sugars – short storage) Polysaccharide (many sugars – energy long storage & form structures)Polysaccharide (many sugars – energy long storage & form structures)

Macromolecule #1: Carbohydrates Polysaccharide Examples:Polysaccharide Examples: Glycogen— stored for future energy needs. Found in liver, muscle & sperm.Glycogen— stored for future energy needs. Found in liver, muscle & sperm. Cellulose— used to form fibers for plant structures. Humans can’t digest (fiber). Most abundant organic molecule.Cellulose— used to form fibers for plant structures. Humans can’t digest (fiber). Most abundant organic molecule. Chitin— exoskeletons of some crustaceans & insects.Chitin— exoskeletons of some crustaceans & insects.

Polysaccharides

Polysaccharides

Macromolecule #2: Lipids Insoluble in water (think oil & water)Insoluble in water (think oil & water) 4 types: 1-triglycerides (fats & oils)1-triglycerides (fats & oils) (long-term energy storage, insulation)(long-term energy storage, insulation) 2-phospholipids (cell membranes)2-phospholipids (cell membranes) 3-steroids (cell signaling)3-steroids (cell signaling) cholesterol molecules modified to form sex hormones. (e.g. testosterone, estrogen, etc.)cholesterol molecules modified to form sex hormones. (e.g. testosterone, estrogen, etc.) 4-waxes (protection, prevents water loss)4-waxes (protection, prevents water loss) Used mainly by plants, but also bees, some furry animals and humans.Used mainly by plants, but also bees, some furry animals and humans.

Triglycerides

Phospholipids

Steroids

Waxes

Macromolecule #3: Proteins Most complicated of all biological molecules.Most complicated of all biological molecules. Serve the most varied purposes, including:Serve the most varied purposes, including: Support structural proteins (e.g., keratin, collagen) structural proteins (e.g., keratin, collagen) Enzymes speed up chemical reactions Transport cell membranes channels, transporters in blood (e.g., Hemoglobin) Defense antibodies of the immune system antibodies of the immune system Hormones cell signaling (e.g., insulin) Motion contractile proteins (e.g., actin, myosin)

Collage n

Antibodies

Cellular Transport

actin & myosin fibers in muscles Motion

Macromolecule #3: Proteins The building blocks of proteins are AMINO ACIDS. There are only 20 types of Amino Acids.The building blocks of proteins are AMINO ACIDS. There are only 20 types of Amino Acids. There are millions of different proteins, and they are all built from different combinations of the 20 amino acids.There are millions of different proteins, and they are all built from different combinations of the 20 amino acids. Amino acids join together to form peptides, polypeptides, and polypeptide chains.Amino acids join together to form peptides, polypeptides, and polypeptide chains.

Macromolecule #4: Nucleic Acids Nucleotides: building blocks of nucleic acids.Nucleotides: building blocks of nucleic acids. Each nucleotide containsEach nucleotide contains (a) phosphate molecule,(a) phosphate molecule, (b) nitrogenous base, and(b) nitrogenous base, and (c) 5-carbon sugar(c) 5-carbon sugar Several types of nucleic acids, including:Several types of nucleic acids, including: DNA: deoxyribonucleic acidDNA: deoxyribonucleic acid Genetic material, double stranded helixGenetic material, double stranded helix RNA: ribonucleic acidRNA: ribonucleic acid Genetic material, single strandedGenetic material, single stranded ATP: adenosine triphosphateATP: adenosine triphosphate High energy compoundHigh energy compound

DNA

Nucleotide Structure

CHEMISTRY IS LIFE…