Biology Unit 1

Science

The organized study of the structure & behavior of the physical & natural world through observation, experimentation, & the testing of theories against the evidence obtained (scientific method)

Scientific Method

Have to observe, ask people (experts), create hypothesis, experiment, get data from experiment & learn if it supports the hypothesis, after finding data you draw conclusions, then find others to look over the data & the conclusion you got from your experiment

Observations

A description, measurement, or record of any object or phenomenon

Hypothesis

An informed, logical, plausible, & testable explanation of the natural world

Independent Variable

The variable you manipulate (is fixed & uses x-axis)

Dependent Variable

What changes as a result of the control (what is measured & uses y-axis)

Controls

Have to compare to see what is more effective (taking something we already know about to compare it to something new to see what is more effective)

Experiment

A repeated manipulation of an aspect of the natural world (designed to test the validity of a hypothesis)

Fact (Evidence)

an indisputable observation of a natural or social phenomenon. We set out to gather evidence to see if our hypothesis is supported

Scientific Theory

Theory about what we think is happening or causes something to

Peer Review

Have to have others to look over what we got in our experiments to get other opinions

Biology

The scientific study of life & its interactions

Levels of Biological Organization

Atoms, molecules, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystems, biosphere

Scientific Fact

It is the evidence obtained about the natural world using the scientific process & rendered to extensive peer-review

Atom

The smallest unit of an element & the basic structural unit

Element

A substance that cannot be broken down into simpler substances

Chemical Reaction

A process that forms & breaks chemical bonds that hold atoms together in molecules

Protons

Positively charged subatomic particles

Neutrons

Uncharged subatomic particles

Electrons

Negatively charge subatomic particles

Atomic Nucleus

The central part of an atom that contains protons & neutrons

Atomic Number

The number of protons in the nucleus

Atomic Mass

The total mass of all the protons, neutrons, & electrons within an atom

Atomic Model

A model used to describe the structure & makeup of an atom

Periodic Table

Organizes the elements according to their atomic numbers & chemical characteristics

Chemical Bond

An attraction between two atoms or molecules that tends to hold them together. Types of bonds include covalent, ionic, & hydrogen

Molecule

A particle composed of one or more atoms held together by chemical bonds; the smallest particle of a compound that displays all the properties of that compound

Ionic Bond

Bond between the opposite electrical charges of positively & negatively charged molecules or ions

Covalent Bond

Electrons are shared between atoms (Ex. The 2 Hydrogen atoms of Hydrogen gas (N₂), The Hydrogen & Oxygen atoms of a water molecule (H₂O))

Hydrogen Bond

Attractions occur between polar molecules in which hydrogen is bounded to oxygen or nitrogen. The slightly positive hydrogen attracts the slightly negative oxygen or nitrogen of a nearby polar molecule (Ex. Occurs between water molecules, slightly positive charges on hydrogen atoms attract slightly negative charges on oxygen atoms of nearby molecules)

Cohesion

The tendency of water molecules to stick together (produces **surface tension**)

Adhesion

The tendency of water molecules to cling to other substances (result is **capillary action:** movement of water into very narrow spaces)

Specific Heat

The amount of energy required to heat 1 gram of a substance by 1 °C

Heat of Vaporization

The amount of heat needed to cause a substance to evaporate

Hydrophobic

Regions of lipids that repel water

Hydrophilic

Region of lipids that do **not** repel water

Solvent

A substance that completely surrounds & disperses the atoms or molecules of another substance

Solute

What is dissolved

Solution

A substance with 1 or more dissolved substances

Acid

Solutions in which H⁺ exceeds the OH⁻

Base

Increases the OH⁻ concentration when dissolved in water

pH Scale

Measures how acidic or basic a solution is based on the concentration of H⁺

Buffer

A molecule that helps maintain a solution at nearly a constant pH

Organic

Made by living things (has carbon & hydrogen)(has a carbon backbone)

Inorganic

(Doesn’t have carbon & hydrogen) (Ex. Water only has hydrogen but no carbon)

Biological Molecules

All molecules produced by living things (Ex. carbohydrates, lipids, proteins, & nucleus acids)

Monomer

Composed of one molecule

Polymer

Composed of many molecules. A molecule composed of 3 or more smaller subunits called monomers

Dehydration Synthesis

The joining of two carbon molecules or chains with the release of a water molecule

Hydrolysis

Breaks apart carbon chains into parts incorporating parts of a water molecule into each of the broken chains

Carbohydrate

A compound composed of carbon, hydrogen, & oxygen, with the approximate chemical formula (CH₂O); includes sugars, starches, & cellulose

Monosaccharide

Single sugar (glucose)

Disaccharide

2 linked sugars (sucrose)

Polysaccharide

Many sugars linked (starches)

Starch

(Insoluble) but can be broken down by enzymes in saliva & taste “sweet”

Glycogen

Short-term storage in animals

Cellulose

(Structural in plants) a component of the cell wall

Chitin

(Structural in animals) highly branched chains of glucose - supports soft bodies of arthropods

Proteins

A polymer composed of amino acids joined by peptide bonds

Enzymes

Proteins that regulate metabolic chemical reactions in cells

Amino Acids

Central carbon, amino group, carboxyl group, and a hydrogen

Disulfide Bond

The covalent bond formed between the sulfur atoms of 2 cysteines in a protein; typically causes the protein to fold by bringing otherwise distant parts of the protein close together

Peptide Bond

Joining 2 amino acids together

Peptide

2 amino acids bonded together

Primary Structure

Sequence of amino acids in a protein

Secondary Structure

Helix or pleated sheet (hydrogen bonded together)

Tertiary Structure

Folding of helix or pleated sheet (hydrogen bonds, disulfide bonds)

Quaternary Structure

Individual peptides linked together (hydrogen bonds, disulfide bonds)

Denatured

When proteins normal structure is destroyed

Nucleotide

Phosphate group, 5-carbon sugar, nitrogen carrying base

Nucleic Acid

Nucleotides linked together

DNA

Deoxyribose nucleic acid, contains the genetic information of all organisms

RNA

Ribonucleic acid, it is involved in converting the genetic information obtained from DNA into a protein

Lipids

One of a number of organic molecules containing large non polar regions composed solely of carbon & hydrogen, which make them hydrophobic & insoluble in water; includes oils, fats, waxes, phospholipids, & steroids

Fatty Acids

Long chains of mostly carbon & hydrogen

Fats

(Saturated) composed of all single carbon-carbon bonds (solid at room temperature)

Oils

(Unsaturated) contain some carbon-carbon double bonds, liquid at room temperature

Triglyceride

Composed of a glycerol & 3 fatty acid chains

Saturated Fatty Acids

Referring to a fatty acid with as many hydrogen atoms as possible bonded to the carbon backbone (therefore, has no double bonds in its carbon backbone)

Unsaturated Fatty Acids

Referring to a fatty acid with fewer than the maximum number of hydrogen atoms bonded to its carbon backbone (therefore, has one or more double bonds in its carbon backbone)

Waxes

Similar to fats (higher melting point, more brittle), highly saturated

Phospholipids

Major component of cell membranes, composed of glycerol, a phosphate group & 2 fatty acid chains

Steroids

Contain four fused carbon rings, 2% of you brain matter

Cell

The smallest unit of life, consisting, at a minimum, of an outer membrane that encloses a watery medium containing molecules, including genetic material composed of DNA

Cell Theory

The scientific theory stating that every living organism is made up of one or more cells; cells are the functional units of all organisms; & all cells arise from preexisting cells

Light Microscope

A tool that can identify, observe & magnify objects by transmitting light through a string of lenses

Electron Microscope

An instrument in which a beam of electrons is used to produce an enlarged image of a very small object

Prokaryotic

Organisms that lack membrane bound organelles (Ex. Bacteria & Archaea Bacteria)

Eukaryotic

Organisms that contain several membrane bound organelles (Ex. Protists, Fungi, Plants, & Animals)

Nucleus

A large organelle that contains genetic material (DNA, RNA)

Plasma Membrane

The outer membrane of the cell, a selectively permeable phospholipid belayer imbedded with proteins

Cytosol

The fluid portion within the plasma membrane

Cytoplasm

All the material contained within the plasma membrane of the cell (except the nucleus)

Protoplasm

The colorless material comprising the living part of a cell, including the cytoplasm, nucleus, nucleus, & other organelles

Cytoskeleton

A network of protein fibers in the cytoplasm that gives shape to the cell, holds & moves organisms, & typically involved in cell movement

Nucleoid

Contains a single circular chromosome; it is not surrounded by a membrane

Plasmids

Small rings of DNA that is exchanged between bacterial cells

Cell Wall

Composed of peptides that link chains of sugars that have amino functional groups that protect & give shape to cells (rod-shaped (bacclli), spherical (cocci), spiral-shaped (spirilla))

Pili

Surface proteins projecting from the cell wall; they may be short & numerous (attachment pili) or long & few (sex pili)

Flagellum

A whip-like structures that rotate to propel a bacteria through fluid environment