AP Bio Unit 1 Terms

Nitrogenous base

A component of a nucleotide which is a cyclic molecule and there are four types

Purine

Double ring structures found in nucleotides

Adenine (A)

A nitrogenous base that is a purine and bonds with thymine or uracil

Guanine (G)

A nitrogenous base that is a purine and bonds with cytosine

Thymine (T)

A nitrogenous base that is a pyrimidine and bonds with adenine

Cytosine (C)

A nitrogenous base that is a pyrimidine and bonds with guanine

Pyrimidine

Single ring structures found in nucleotides

Directionality/Polarity

Helps to distinguish the orientation of a DNA strand

5’ end

A nucleotide at the top with 5’ phosphate free

3’ end

A nucleotide at the bottom with a 3’ hydroxyl group free

Double helix

The structure of DNA, two strands wrapped around eachother

Antiparallel

Strands within DNA that run in opposite directions (5’-3’ and 3’-5’)

Complementary

Base pairs (A-T and G-C)

Uracil (U)

A nitrogenous base in RNA

Central dogma

The flow of information in all organisms

Nucleotides

The monomers of nucleic acids with three parts

Deoxyribose sugar

A five carbon sugar that is located in DNA and is apart of a nucleotide

Ribose sugar

A five carbon sugar that is located in RNA and is apart of a nucleotide

Peptide bond

The covalent linking of amino acids, formed in a dehydration synthesis reaction

Peptide

A short polymer of amino acids

Polypeptide

A long polymer of amino acids

Primary structure

Linear sequence of amino acids in a protein

Secondary structure

Structural proteins held together by hydrogen bonds

Alpha helix

The coil formation of a secondary structure

Beta sheet

The zig-zag formation of a secondary structure formed by extended polypeptide strands

Tertiary structure

The three-dimensional shape for a single polypeptide chain, its structure can be determined through hydrogen and ionic bonds, distribution of R groups

Quaternary structure

Two or more 3-D polypeptide chains

Polar

A molecule with positive and negative regions

Hydrogen bond

The weak attraction of a hydrogen atom with another atom through polar charges

Cohesion

Water's attraction to water molecule

Adhesion

Water's attraction to other materials

Surface tension

How difficult it is to break the surface of a liquid (high for water)

Specific heat

The amount of energy required to change a substance's temperature

Solvent

A liquid capable of dissolving substances

Acid

Molecules that donate H+, <7 on pH scale

Base

Molecules that receive a H+, >7 on pH scale

pH scale

A way to describe how acidic or basic a solution is, ranges from 0-14

Dehydration synthesis reaction

Chemical reaction where water is removed while forming two monomers into a polymer

Hydrolysis reaction

Chemical reaction where covalent bonds are broken by adding water

Matter

Anything that has mass and takes up space

Atoms

Basic units of matter

Molecule

Chemical structure made up of two or more atoms

Organic molecule

Biological molecules that contain carbon

Nucleus

Control center of the cell

Protons

Positively charged particles within the nucleus

Neutrons

Neutral charged particles within the nucleus

Electrons

Negatively charged particles which surround the nucleus

Atomic number

The amount of protons in an atom

Element

A pure substance that consists of one sole atom

Atomic mass

Composed of protons and neutrons, each having a mass of 1 atomic unit

Isotope

Atoms of the same element which have different numbers of neutrons

Ion

A charged atom (cation and anion)

Energy level

Where electrons are located outside of the nucleus, a specific, fixed location

Electron shell

Represents an energy level

Valence electron

Electron in the outermost energy level

Periodic table of the elements

Arrangement of elements which describes valence electrons and other properties of elements

Chemical bond

The forming of individual molecules

Covalent bond

Pair of electrons shared between two atoms

Single bond

1 pair of electrons shared among two atoms

Double bond

2 pairs of electrons shared among two atoms

Electronegativity

An atoms strength and ability to attract electrons

Polar covalent bond

When electrons are unevenly shared (partial positive and negative)

Nonpolar covalent bond

When electrons are shared equally

Ionic bond

A bond with oppositely charged ions, one donates an electron

Chemical reaction

A process where atoms or molecules transform into different molecules (product and reactant)

Reactant

The atoms or molecules that are changed in a chemical reaction

Product

The molecules formed by a chemical reaction

Polymer

Long chain (compound) of repeating monomers

Monomer

Small molecular building blocks

Protein

An organic molecule that provides function and structure to a cell

Amino acid

The monomer (sub unit) of protein

Nucleic acid

An organic molecule that contains genetic information in a cell, DNA or RNA

Ribonucleic acid (RNA)

A type of nucleic acid

Nucleotide

The monomer of nucleic acid

Carbohydrate

An organic molecule used as quick energy composed of sugar(s)

Lipid

An organic molecule that is hydrophobic and used for long term energy

Hydrophobic

Nonpolar molecules that do not dissolve in water

Hydrophilic

Polar molecules that dissolve in water

Biology

The scientific study of life

Biologist

Person who studies biology

Organism

A living creature that displays all properties of life

Gene

Unit of heredity (instruction manual made of DNA)

Genome

The genetic information contained in a cell

Cell

The most basic structure of life that makes up an organism

Species

A group of interbreeding organisms which produce offspring (are distinguishable)

Evolution

Change over time (adaptation)

Natural Selection

A mechanism where some creatures survive and reproduce more than others as a result of variation in a specific environment

Energy

The ability to do work, and is essential for life

Energetics

The study that explores properties of energy and its distribution in biological, chemical, and physical processes

DNA (deoxyribonuleic acid)

The carrier of genetic information for all organisms

Biological System

A complex network made up of biotic and abiotic entities

Biotic

living, or once living organisms in a system

Abiotic

non living chemical and physical factors in a system

System

A complex group of organized, interacting components

Scientific Inquiry

The process scientists use to question the natural world in an ordered and deliberate way

Observation

Act of viewing the world around us (focused question)

Hypothesis

A tentative explanation for one or more observations where evidence can help support or reject it

Controlled experiment

An experiment with at least two groups of identical and one singular change is introduced

Test/Experimental group

Experiences the variable in an experiment

Control group

The group not exposed to the variable in an experiment