Honors Bio LT 1-4: Process of Science; Matter and Bonding; Organic Compounds

Vocabulary flashcards covering key terms from the lecture notes on the Process of Science, Matter and Bonding, and Organic Compounds.

Science

The systematic study of the natural world through observations, hypotheses, experiments, and testing.

Inquiry

The search for information and explanation.

Observation

Careful noting and recording of information about natural phenomena.

Data

Recorded observations that can be qualitative or quantitative.

Qualitative data

Descriptive data, not numerical measurements.

Quantitative data

Numerical measurements, often organized in tables and graphs.

Inductive reasoning

Drawing general conclusions from many observations.

Hypothesis

A testable prediction guided by observations; an explanation on trial; not proven.

Deductive reasoning

Reasoning from general premises to specific results.

Controlled experiment

An experiment comparing an experimental group with a control group, using variables.

Independent variable

The factor deliberately changed by the researcher.

Dependent variable

The factor measured; the effect of the independent variable.

Control group

Group not exposed to the manipulated factor; baseline for comparison.

Theory

A broad, testable explanation supported by a large body of evidence; can lead to new hypotheses.

Matter

Anything that takes up space and has mass.

Element

A substance that cannot be broken down into other substances by chemical reactions.

Compound

Substance consisting of two or more elements in a fixed ratio.

Essential elements

Elements required by organisms for life; about 20–25% of natural elements.

Trace elements

Elements required only in minute quantities.

Atomic number

Number of protons in an atom.

Mass number

Sum of protons and neutrons in the nucleus.

Atomic mass

The atom’s total mass; approximated by the mass number.

Isotopes

Atoms of the same element that differ in the number of neutrons; some are radioactive.

Proton

Positively charged subatomic particle in the nucleus.

Neutron

Electrically neutral subatomic particle in the nucleus.

Electron

Negatively charged subatomic particle in electron shells surrounding the nucleus.

Valence electrons

Electrons in the outermost shell that participate in bonding.

Covalent bond

Sharing of a pair of valence electrons between atoms.

Molecule

Two or more atoms held together by covalent bonds.

Nonpolar covalent bond

Equal sharing of electrons between atoms.

Polar covalent bond

Unequal sharing of electrons due to differences in electronegativity.

Ionic bond

Transfer of electrons; attraction between a cation and an anion.

Cation

Positively charged ion.

Anion

Negatively charged ion.

Hydrogen bond

Attraction between a hydrogen covalently bonded to an electronegative atom and another electronegative atom (usually O or N).

Van der Waals interactions

Weak attractions between molecules that are very close.

Chemical reaction

Breaking and forming of chemical bonds; reactants become products; reversible; chemical equilibrium can be reached.

Reactants

Starting substances in a chemical reaction.

Products

Substances produced by a chemical reaction.

Dehydration synthesis

Building a polymer by removing a water molecule.

Hydrolysis

Breaking down a polymer by adding water.

Organic chemistry

Study of carbon-based compounds.

Carbon

Element that forms four covalent bonds; backbone of life; can form tetrahedral and other shapes.

Hydrocarbons

Compounds consisting of carbon and hydrogen only.

Functional group

Component of organic molecules most involved in chemical reactions; determines properties.

Hydroxyl group

-OH; polar; forms hydrogen bonds; increases solubility (e.g., in alcohols like ethanol).

Carbonyl group

C=O; present in ketones (within skeleton) and aldehydes (at the end).

Aldehyde

Carbonyl group at the end of a carbon skeleton.

Ketone

Carbonyl group within the carbon skeleton.

Carboxyl group

-COOH; acts as an acid; ionizes to form carboxylate.

Amino group

-NH2; acts as a base; common in amino acids.

Sulfhydryl group

-SH; can form disulfide cross-links that stabilize protein structure.

Phosphate group

-PO4; contributes negative charge; can release energy when hydrolyzed.

Monomer

Small building block that can join to form polymers.

Polymer

Long molecule made of repeating monomer units.

Glycogen

Storage of glucose in animals.

Starch

Storage of glucose in plants.

Cellulose

Structural component of plant cell walls.

Chitin

Structural component in animal exoskeletons.

Monosaccharide

Simple sugar; e.g., glucose; monomer of carbohydrates.

Disaccharide

Two monosaccharides linked together.

Polysaccharide

Long polymer of monosaccharides (e.g., glycogen, starch, cellulose).

Glucose

A common monosaccharide used for energy; C6H12O6.

Glycerol

Alcohol component of lipids; backbone of triglycerides and phospholipids.

Fatty acid

Long hydrocarbon chain with a carboxyl group; components of lipids.

Triglyceride

Glycerol bonded to three fatty acids; main form of fat storage.

Phospholipid

Glycerol + two fatty acids + phosphate; forms membranes.

Steroids

Lipids with four fused rings; include cholesterol.

Hydrophobic

Not water soluble.

Proteins

Macromolecules made of amino acids; perform many roles including enzymes, antibodies, movement, hormones, and oxygen transport.

Amino acid

Monomer of proteins; has amino group, carboxyl group, R group, and central carbon.

Peptide bond

Covalent bond linking amino acids in a protein.

Polypeptide

Long chain of amino acids.

Enzyme

Biological catalyst that speeds up chemical reactions.

Antibody

Protein of the immune system.

Hemoglobin

Protein in blood that carries oxygen.

Nucleic acid

DNA and RNA; store and transmit genetic information.

Nucleotide

Monomer of nucleic acids; consists of sugar, phosphate, and base.

DNA

Deoxyribonucleic acid; genetic material; usually a double helix.

RNA

Ribonucleic acid; usually single-stranded; involved in protein synthesis.

Double helix

Twisted ladder structure of DNA formed by two strands.

Base pairs

Pairs of nucleotides on DNA: A-T and C-G (in DNA); A-U and C-G in RNA.

Deoxyribose

Sugar in DNA.

Ribose

Sugar in RNA.

Gene expression

Process: DNA -> RNA -> Protein; leads to traits.