Unit 1: Chapter 2-Biology

Introductory Biology
STUDY
PLAY

Terms in this set (...)

Atom
The smallest unit of matter that retains the properties of an element.
Subatomic particles
protons, neutrons, and electrons
Proton
A subatomic particle that has a positive charge and that is found in the nucleus of an atom
Neutrons
The particles of the nucleus that have no charge
Electrons
Negatively charged particles
Mass of electron
1/1840 of a proton
Element
A pure substance that consists entirely of one type of atom
Isotope
Atoms of the same element that have different numbers of neutrons
Isotopes of carbon are
C12, C13, C14
Why do isotopes have the same chemical properties
Because they have the same number of electrons
What are the two main types of chemical bonds
Ionic and Covalent
Ionic bond
when electrons are transferred from one atom to another
Covalent bonds
Form when electrons are shared between atoms
Ion
A particle that is electrically charged (positive or negative)
Molecule
A combination of two or more atoms
van der Waals forces
Intermolecular forces of attraction
Polarity
A property of a molecule with oppositely charged ends. Because of it, water is able to dissolve many different substances
Adhesion
An attraction between molecules of different substances
Cohesion
An attraction between molecules of the same substances
Mixture
when two or more elements or compounds are physically mixed together but not chemically combined.
Types of mixtures
Solutions and suspensions
Solute
The substance that is dissolved
Chemical compound
formed by the combination of two or more elements in definite proportions
Solution
A homogeneous mixture of two or more substances
Solvent
Substance in which a solute is dissolved to form a solution
Suspension
A mixture in which fine particles are suspended in a fluid where they are supported by buoyancy
Acid
A compound that forms hydrogen ions (H+) in solution
Base
A compound that produces hydroxide ions (OH+) in solution
Buffers
Weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH
Importance of acids to humans
HCl is found in the stomach and helps with digestion
Human beings are made up of what elements?
Carbon, hydrogen, oxygen, phosphorous, sulfur, nitrogen
Four main macromolecules
Carbohydrates, lipids, proteins and nucleic acids
Carbohydrates
Compounds made up of carbon, hydrogen, and oxygen atoms
Function of carbohydrates
Source of energy and structure
Lipids
Large and varied group of biological molecules that are generally not soluble in water
Functions of lipids
Store energy, waterproof surfaces/covering and as parts of a biological membranes
Nucleic acids
Macromolecules that contain hydrogen, oxygen, nitrogen, carbon and phosphorus.
Functions of nucleic acids
Store and transmit hereditary or genetic information
Proteins
Macromolecules that contain nitrogen as well as carbon, hydrogen, and oxygen.
Function of proteins
Control the rate of reactions, regulate cell processes, some are used to form bones and muscles, transport substances into or out of cells or help fight diseases
Strong forces bind protons and neutrons together to form ______________ at the center of the atom
Nucleus
Molecule
The structure that results when atoms are joined together by covalent bonds
Hydrogen bond
The attraction between a hydrogen atom on one water molecule and the oxygen atom on another
Monomers
Smaller units of macromolecules
Polymers
Large units of made up of monomers
Many organisms store extra sugar as complex carbohydrates known as
Starch
Single sugar molecules are also known as
Monosaccharides
Many animals store excess sugar in a polysaccharide called
Glycogen
Plants use a slightly different polysaccharide, called
Starch
Plants also make another important polysaccharide called
Cellulose
Many steroids, such as hormones, serve as
Chemical messengers
Many lipids are formed when a glycerol molecule combines with compounds called
Fatty acid
If each carbon atom in a lipid's fatty acid chains is joined to another carbon atom by a single bond, the lipid is said to be
Saturated
If there is at least one carbon-carbon double bond in a fatty acid, the fatty acid is said to be
Unsaturated
Lipids whose fatty acids contain more than one double bond are said to be
Polyunsaturated
Nucleic acids are polymers assembled from individual monomers known as
Nucleotides
RNA contains the sugar
Ribose
DNA contains the sugar
Deoxyribose
Proteins are polymers of molecules called
Amino acids
Amino acids
Compounds with an amino group (-NH2) on one end and a carboxyl group (-COOH) on the other end
Protein secondary structure
Is formed by the folding or coiling of the polypeptide chain
A protein's primary structure
Is the sequence of its amino acids.
A protein's tertiary structure
Is the complete, three-dimensional arrangement of a polypeptide chain.
YOU MIGHT ALSO LIKE...