Chapter 2: Introduction to chemistry of life Flashcards
Atoms
is the smallest unit of ordinary matter that forms a chemical element.
Element
contains only one type of atom, e.g., carbon, sulfur, or hydrogen.
Compounds
Substances containing two or more types of atom combined
Proton
a stable subatomic particle occurring in all atomic nuclei, with a positive electric charge
Neutrons
a subatomic particle of about the same mass as a proton but without an electric charge
Electron
a stable subatomic particle with a charge of negative electricity,
Atomic number
the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.
Atomic weight
total weight of an atom
Isotopes
• An element with a similar chemical make-up and the same atomic number, but different atomic weights to another or others.
Chemical compound
is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds.
Molecules
consist of two or more atoms that are chemically combined.
Chemical bond
a lasting attraction between atoms, ions, or molecules that enables the formation of chemical compounds.
Covalent bonds
a chemical bond that involves the sharing of electron pairs between atoms.
Ionic bonds
is a chemical link between two atoms caused by the electrostatic force between oppositely charged ions in an ionic compound.
Electrolytes
are minerals that carry an electrical charge when dissolved in water.
pH scale
The pH scale measures how acidic or basic a substance is. The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic. A pH greater than 7 is basic.
Acidosis
occurs when your kidneys and lungs can’t keep your body’s pH in balance.
Alkalosis
occurs when your body has too many bases. It can occur due to decreased blood levels of carbon dioxide, which is an acid.
Carbohydrates
(sugars and starches) are composed of carbon, oxygen and hydrogen.
Glucose
Glucose is one of the body’s preferred sources of fuel in the form of carbohydrates. It , is a monosaccharide (mono = one; saccharide = sugar).
Functions of sugar
- providing a ready source of energy to fuel cell metabolism
- providing a form of energy storage, e.g., glycogen
- forming an integral part of the structure of DNA and RNA
- acting as receptors on the cell surface, allowing the cell to recognize other molecules and cells.
Amino acids
organic compounds that combine to form proteins.
Lipids
is any of various organic compounds that are insoluble in water (they are hydrophobic).
They are made up mainly of carbon, hydrogen, and oxygen atoms, and some contain additional elements, like nitrogen or phosphorus.
Fats
are classified as saturated or unsaturated, depending on the chemical nature of the fatty acids present.
Nucleotides
a compound consisting of a nucleoside linked to a phosphate group. Nucleotides form the basic structural unit of nucleic acids such as DNA.
Nucleic acids
a complex organic substance present in living cells, especially DNA or RNA, whose molecules consist of many nucleotides linked in a long chain.
Enzymes
are proteins that act as catalysts for biochemical reactions – that is, they speed the reaction up but are not themselves changed by it, and therefore can be used repeatedly.
Diffusion
refers to the movement of molecules from an area of high concentration to an area of low concentration, and occurs mainly in gases, liquids, and solutions.
Osmosis
refers specifically to the diffusion of water down its concentration gradient.
Extracellular fluid (ECF)
denotes all body fluid outside the cells.
ECF consists mainly of blood, plasma, lymph, cerebrospinal fluid and fluid in the interstitial spaces of the body.
Intracellular Fluid (ICF)
• The composition of intracellular fluid (ICF) is largely controlled by the cell itself because there are selective uptake and discharge mechanisms present in the cell membrane.
Buffers
• Acids and bases are constantly produced in the body by various cellular activities. However, the pH of the body fluids is maintained within a narrow range by buffer mechanisms.
