Chapter 1-5 BIO189

What is Science?

A study of the natural world via direct observation and systematic experimentation.

Scientific Method

A standardized approach based on experimentation and observation to test ideas and answer questions.

Steps of the Scientific Method

1. Make observations 2. Ask questions 3. Develop hypotheses 4. Experimentation 5. Analyzing data 6. Drawing conclusions.

Hypothesis must be _____.

Testable and falsifiable.

Theory

A comprehensive explanation for natural phenomena based on numerous studies.

What are the six main elements of life, represented by the acronym NCHOPS?

Nitrogen (N), Carbon (C), Hydrogen (H), Oxygen (O), Phosphorus (P), Sulfur (S).

Matter

Anything with mass that occupies physical space in the universe.

Atoms

The smallest individual particles of matter.

Nuclear fusion

When two nuclei fuse together to make a different, larger element.

Radioactive decay

The process by which unstable nuclei spontaneously decay.

Chemical bond

The attraction between atomic nuclei through sharing or stealing electrons.

Molecule

Any two or more atoms chemically bonded.

Compound

A molecule made of atoms from two or more different elements.

Ionic bond

Forms between two atoms with very different electronegativities.

Covalent bond

Occurs when two atoms share electrons in pairs.

Functional groups

Specific arrangements of atoms in a compound responsible for characteristic reactions.

Polymer

Macromolecules composed of numerous covalently-linked units called monomers.

Dehydration Synthesis

The chemical reaction connecting monomers to form polymers.

Carbohydrates

Macromolecules also known as saccharides or sugars.

Polypeptide

A chain of at least 20-30 amino acids.

Central dogma of biology

The flow of information from DNA to RNA to Protein.

Transcription

The process of converting DNA sequence into a temporary RNA sequence.

Translation

The process of converting RNA sequence into an amino acid sequence.

Primary structure of protein

The sequence of amino acids in a linear polypeptide chain.

Secondary structure of protein

Hydrogen bonding resulting in structures like alpha helix and beta sheets.

Tertiary structure of protein

Final 3-D folded shape of a single polypeptide chain.

Quaternary structure of protein

Complex formed when multiple independently-folded proteins associate.

Nucleus

The region of a cell that houses and protects the DNA.

Cell membrane

A lipid-rich bilayer studded with proteins and carbohydrates.

Ribosomes

RNA/protein organelles that synthesize proteins from RNA codes.

Chloroplasts

Organelles that perform photosynthesis in plant cells.

Catalyst (enzyme)

A substance that increases the rate of a chemical reaction without undergoing permanent change.

Active site

The physical location on the enzyme where the substrate associates.

Osmosis

Movement of water molecules between two solutions with different solute concentrations.

Isotonic solution

A solution with the same solute concentration as another solution.

Hypertonic solution

A solution with a higher solute concentration compared to another.

Hypotonic solution

A solution with a lower solute concentration compared to another.