Bio 101 Chs. 1 and 2

Atom

the smallest unit of an element

Parts of the atom: proton

positive charge, located in nucleus

Parts of the atom: neutron

no charge, located in nucleus

Parts of the atom: electron

negative charge, located outside the nucleus (energy shells)

Four Levels of Biological Organization: cell

the smallest unit of life

Four Levels of Biological Organization: tissue

group of similar cells that perform a particular funciton

Four Levels of Biological Organization: organ

composed of tissues functioning together for a specific task

Four Levels of Biological Organization: organ system

composed of several organs working together

Energy

the capacity to do work

Genes

units of information within an individuals DNA

Reproduction

process by which an organism makes more of itself

Homeostasis

requirement that organisms maintain a relatively constant internal temperature

Natural Selection

differential reproductive success of adapted individuals

Stimuli

something causing a response

How do organisms respond to stimuli?

with behavior (ex: movement)

Classification: Domain Archaea

unicellular, no nucleus, survive in extreme environments

Classification: Domain Bacteria

unicellular, found almost everywhere

Classification: Domain Eukarya

cells with a true nucleus, further categorized

Categories of Classification, most inclusive to least inclusive

domain, kingdom, phylum, class, order, family, genus, species

Biology

the scientific study of life

Hypothesis

tentative explanation for the natural event

Control

something kept normal or unchanged to be compared to

Model

a representation of an actual subject

Theory

supported by a broad range of observations, experiments, and data

Variables: Independent

factor of the experiment being tested or controlled

Variables: Dependent

result or change that occurs due to the independent variable

Matter

anything that has mass and takes up space

Elements

substances that cannot be broken down into simpler substances by ordinary chemical means

Elements that make up 95% of organisms by weight

carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur

Molecules

form when two or more of the same elements bond together

Compound

form when two or more different elements bond together

Acids

release hydrogen ions when dissociated in water

Bases

dissociate in water, release hydroxide ions or take up hydrogen ions.

pH Scale

indicates the acidity or alkalinity of a solution, on a scale of 0-14

What two elements do organic molecules always have?

carbon and hydrogen

Carbohydrates: Monosaccharide

simple sugars with 3-7 carbon atoms

Carbohydrates: Disaccharide

contain two or more monosaccharides joined by the dehydration reaction

Carbohydrates: Polysaccharides

long polymers that contain many glucose subunits

Starch

storage form of glucose in plants

Glycogen

storage form of glucose in animals

Lipids

contain more energy per gram than other biological molecules

Fats

animal origin, solid at room temperature

Oils

plant origin, liquid at room temperature

Emulsification

the breakdown of fat into tiny particles that are water soluble

Saturated Fat

no double bonds between carbon atoms

Unsaturated Fat

one or more double bonds between carbon atoms

Trans-Fatty Acids

man-made; help foods have a longer shelf life but are harmful for human health

Phospholipid

composed of two fatty acid tails and a phosphate head

Steroids

have a backbone of four fused carbon rings

Proteins

Polymers composed of amino acid monomers

Protein Example and Function

enzymes which speed up chemical reactions

Nucleic Acids: DNA

deoxyribonucleic acid, stores genetic information in the cell and in the organism; contains thymine

Nucleic Acids: RNA

ribonucleic acid, involved in decoding and regulation of gene expression, contains uracil

What three things are each nucleotide made of?

phosphate, pentose sugar, nitrogen-containing base

ATP

adenosine triphosphate, spendable form of energy in cells

Hydrolization

breaking apart by water

ADP

adenosine diphosphate, formed by the hydrolization of ATP

What are the properties of water?

high heat capacity, high heat of vaporization, solvent, water molecules are cohesive and adhesive, high surface tension, frozen water is less dense than liquid water

calorie

the amount of heat energy needed to raise the temperature of 1 gram of water 1 degree C

Vaporization

the process of changing from a liquid to a gas

Two types of vaporization

Evaporation, Boiling

Polar

both positive and negative charged areas of the molecule

Solution

contains dissolved substances

Solvent

what does the dissolving (EX: water)

Cohesion

water molecules will cling together because of hydrogen bonding

Adhesion

water’s positive and negative poles allow it to adhere to surfaces

surface tension

the ability of a surface of a liquid to act like a thin, flexible film