Anatomy and Physiology- Chemistry

Introduction Chemistry is the branch of science that considers the composition of matter and how this composition changes. Chemistry is essential for understanding anatomy and physiology because body structures and functions result from chemical changes within cells.

Structure of Matter Matter is anything that has mass (weight) and takes up space. Matter is found in various forms, gases, liquids, and solids Elements make up all matter. Elements are composed of tiny particles called atoms. The smallest complete units of elements are atoms.

Atomic Structure Nucleus is the central portion of the atom which contains neutrons (neutral) and protons (positive). Electrons: found outside the nucleus in energy shells or levels or rings have a negative charge. Protons and electrons

Bond Types 3 Main Types Ionic bond between a metal and nonmetal they transfer electrons forming ions. Ion atoms that gain or lose electrons (-) become electrically charged. Covalent bond between two nonmetals they share electrons. When atoms combine with other atoms, they can share an electron with another atom, lose an electron or gain an electron. Hydrogen Bonds

Molecules and Compounds A molecule is formed when two or more atoms combine. If atoms of different elements combine, the resulting structure can also be called a compound. Examples: Baking soda, sugar Molecular formula represents the numbers and types of atoms in a molecule. Examples… H2O & C6H12O6

Chemical Reactions: Synthesis-when two or more atoms or reactants bond to form a new, more complex structure. Synthesis requires energy and is important to the growth of body parts.

Catabolism These reactions tear down molecules Example: Cellular respiration-breaks down oxygen and glucose to produce ATP (energy)

Anabolism These reactions build biomolecules from smaller ones Example: Amino acids join together to make proteins in the body

Enzymes Catalysts affect the speed of a reaction but is not consumed by the reaction. Enzymes speed up chemical reactions in the body by lowering activation energy. This allows the body to keep up with demand.

Acids and Bases pH scale ranges from 0 to 14. It indicates how acidic something is. Acids have pH less than 7 Neutral pH equal to 7 Bases have pH greater than 7

Chemical Constituents of Cells 2 types of chemicals Organic compounds must contain carbon and hydrogen but may contain other elements as well. (C6H12O6). Inorganic- all the other compounds (H20) do NOT contain C.

Inorganic Compounds Water Oxygen Salts

Water In the human body, water plays an important role in dissolving solid substances, moving chemicals around the body, and absorbing and moving heat Is the most abundant compound in cells and is a solvent in which chemical reactions occur. Transports chemicals and heat.

Oxygen Releases energy from glucose and other nutrients. This energy drives metabolism.

Carbon Dioxide Is an inorganic substances that is a metabolic waste product, exhaled from the lungs.

Salts Provide a variety of ions that metabolic processes require.

Organic Compounds Carbohydrates Lipids Proteins Nucleic acids

Carbohydrates Supply most of the energy needed by cells Composed of C,H,O Monosaccharides (simple sugars) Disaccharides are two sugars joined together Polysaccharides, such as starch, are built of many sugars. Humans synthesize the complex carbohydrate called glycogen.

Lipids Lipids made of C,H,O but in different amounts Lipids include fats (most common), steroids, and phospholipids. A fat that has all of its carbon atoms joined by single carbon to carbon bonds is said to be saturated. (solid at room temp, bad for you) Unsaturated fats (liquid at room temp, good for you, double bonds) Cholesterol, estrogens, and testosterone are all steroids. A phospholipid typically has two fatty acid chains and a phosphate group.

Lipids

Proteins Proteins have a great variety of functions in the body---as structural materials, as energy sources, as certain hormones, as receptors on cell membranes, as antibodies, and as enzymes to catalyze metabolic reactions. Proteins contain C,H,O,N, sometimes S Building blocks of proteins are the amino acids (20) Proteins have complex shapes held together by hydrogen bonds. (their many shapes changes their functions) Protein shapes, which determine how proteins function, can be altered by pH, temperature, radiation, or chemicals. Denature means to break apart the protein, and it can no longer function

Protein

Nucleic Acids Nucleic acids form genes and take part in protein synthesis. They contain the elements C,H,O,N,P The building blocks are called nucleotides. Nucleic acids are of two major types: DNA (with deoxyribose) and RNA (with ribose).

Nucleotides

DNA & RNA -Deoxyribonucleic acid: DNA (deoxyribonucleic acid) stores the molecular code in genes. Has 2 strands Deoxy means without oxygen -Ribonucleic acid: RNA (ribonucleic acid) functions in protein synthesis. Has 1 strand