Biology Key Concepts: Cells, Genetics, and Ecosystems

The scientific study of life

Biology

Order, growth and development, reproduction, energy processing, response to environment, regulation, evolutionary adaptation

Characteristics of life

The smallest unit of life that can perform all life functions

Cell

New properties that arise from the interaction of parts

Emergent properties

Small cells with no nucleus or membrane-bound organelles

Prokaryotic cells

Examples of prokaryotes

Bacteria and Archaea

Cells with a nucleus and membrane-bound organelles

Eukaryotic cells

The molecule that stores genetic information

DNA

A segment of DNA that codes for a protein

Gene

DNA → RNA → Protein

Central dogma

Organism that makes its own food using sunlight

Producer (autotroph)

Organism that gets energy by eating other organisms

Consumer (heterotroph)

Energy enters as sunlight and leaves as heat

Energy flow in ecosystems

Process where individuals with favorable traits survive and reproduce more

Natural selection

A trait that increases survival in a particular environment

Adaptation

Anything that has mass and takes up space

Matter

A pure substance that cannot be broken down further

Element

Two or more elements chemically combined

Compound

Positively charged particle in the nucleus

Proton

Neutral particle in the nucleus

Neutron

Negatively charged particle around the nucleus

Electron

Atoms share electrons

Covalent bond

Atoms transfer electrons creating ions

Ionic bond

Weak attraction between polar molecules

Hydrogen bond

Unequal sharing of electrons creates partial charges

Water polarity

Water molecules stick to each other

Cohesion

Water molecules stick to other surfaces

Adhesion

Water molecules stick to other surfaces

Adhesion

Water resists temperature changes

High specific heat of water

Substances that dissolve in water

Hydrophilic

Substances that repel water

Hydrophobic

A substance that releases H+ ions

Acid

A substance that removes H+ or releases OH-

Base

Measures acidity or basicity

pH scale

Forms four covalent bonds allowing complex molecules

Carbon

Groups of atoms that give molecules specific properties

Functional groups

A large molecule made of repeating monomers

Polymer

A small building block molecule

Monomer

Joins monomers by removing water

Dehydration reaction

Breaks polymers by adding water

Hydrolysis

Molecules used for energy and structure

Carbohydrates

Simple sugar such as glucose

Monosaccharide

Long chain of sugar molecules

Polysaccharide

Hydrophobic molecules such as fats and phospholipids

Lipids

Glycerol plus three fatty acids

Triglyceride

Main component of cell membranes

Phospholipid

Macromolecules made of amino acids

Proteins

Building blocks of proteins

Amino acids

DNA and RNA that store genetic information

Nucleic acids

Sugar + phosphate + nitrogen base

Nucleotide