General Biology: Cell Biology, Taxonomy, Biological Chemistry, and Scientific Method

Flashcards providing comprehensive coverage of key biological terms, definitions, taxonomy, biological molecules, and cellular structures from the lecture notes.

Prokaryotes

Single-celled organisms that do not have a nucleus, where DNA is located in the cytoplasm.

Eukaryotes

Usually multi-celled organisms whose cells contain a nucleus that holds their DNA.

Human Taxonomic Classification

Kingdom: Animalia, Phylum: Chordata, Class: Mammalia, Order: Primates, Family: Homindae, Genus: Homo, Species: Sapiens.

Biodiversity

The diversity of life.

Atom

The fundamental building block of all matter.

Molecule

An association of two or more atoms.

Cell

The smallest unit of life.

Organism

An individual that consists of one or more cells.

Population

A group of individuals of a species in a given area.

Community

All populations of all species in a given area.

Ecosystem

A community interacting with its environment.

Biosphere

All regions of Earth that hold life.

Energy

The capacity to do work, which flows in a one-way path through the biosphere.

Nutrients

Substances necessary for survival that an organism cannot make for itself, which are recycled through the biosphere.

Producers

Organisms that make their own food using energy and simple raw materials from non-biological sources.

Consumers

Organisms that obtain energy and nutrients by feeding on other organisms.

Homeostasis

Process by which an organism keeps its internal conditions within a range that favors survival by sensing and responding to change.

Growth

Increase in size, volume, and number of cells in multi-celled species.

Development

Process by which the first cell of a new individual becomes a specialized, multi-celled adult.

Reproduction

Process by which individuals produce offspring.

Inheritance

Transmission of DNA to offspring.

DNA (Deoxyribonucleic Acid)

Molecules that carry hereditary information guiding development and activities, consisting of 4 nucleotides: Adenine, Thymine, Cytosine, and Guanine.

Taxonomy

The practice of naming and classifying species.

Species

A unique kind of organism that can interbreed.

Genus

A group of species that share a set of unique traits.

Protists

The simplest eukaryotes that display great diversity.

Fungi

Eukaryotic consumers that break down food externally.

Plants

Usually multicelled, photosynthetic eukaryotes.

Animals

Multi-celled consumers that ingest food or juices of other organisms.

Science

Systematic study of the observable world.

Scientific Method

Systematically making, testing, and evaluating hypotheses.

Hypothesis

A testable explanation for a natural phenomenon.

Critical Thinking

The deliberate process of judging the quality of information before accepting it.

Sampling Error

The error that may occur because data is collected from only a subset (small group) of the whole group.

Probability

The measure, expressed as a percentage, of the chance that a particular outcome will occur.

Statistically Significant

Refers to a result that has a very low probability of occurring by chance alone.

Independent Variable

The variable that you deliberately plan to change or manipulate in an experiment.

Dependent Variable

The variable that is measured as the results, which responds to whatever is deliberately changed.

Controlled Variables

Things that are purposely kept the same amongst all groups in an experiment.

Experimental Group

A group of individuals who have a certain characteristic or receive a certain treatment.

Control Group

A group not exposed to the independent variable being tested.

Scientific Theory

A hypothesis that has not been disproven after many years of rigorous testing, consistent with all gathered data, and useful for making predictions, though never proven absolutely.

Law of Nature

A phenomenon observed to occur in every circumstance without fail, even without a complete scientific explanation.

Atomic Number

The number of protons in the nucleus of an atom, which determines the element's name.

Mass Number

The total number of particles (protons plus neutrons) in an atom's nucleus.

Element

A pure substance that consists only of atoms with the same number of protons.

Isotope

Form of an element containing the same number of protons but a different number of neutrons, changing its mass number.

Radioisotope

An isotope with an unstable nucleus that spontaneously emits energy and subatomic particles.

Radioactive Decay

Process occurring when atoms spontaneously emit energy and subatomic particles as their nucleus disintegrates.

Ion

A charged atom carrying an unequal number of protons and electrons.

Compound

A molecule that contains atoms of more than one element.

Chemical Bond

An attractive force that arises between two atoms when their electrons interact.

Ionic Bond

A strong mutual attraction formed between ions of opposite charge.

Covalent Bond

A bond formed when two atoms share pairs of electrons.

Cohesion

The tendency of molecules to stick together.

Salt

A compound that dissolves easily in water and releases ions other than $H^+$ and $OH^-$.

Solvent

A liquid that can dissolve other substances.

Solute

A dissolved substance.

Solution

A homogeneous mixture, such as salt dissolved in water.

Hydrophobic

Water-repelling property; resists dissolving in water.

Hydrophilic

Water-loving property; dissolves easily in water.

Acid

A substance that releases $H^+$ ions and has a pH less than $7$.

Base

A substance that accepts $H^+$ ions and has a pH greater than $7$.

Organic Molecule

A type of molecule consisting primarily of carbon and hydrogen atoms, covalently bonding with up to $4$ other atoms.

Monomer

A single subunit of a polymer, such as glucose, fatty acids, amino acids, or nucleotides.

Polymer

A chain of monomers, such as carbohydrates, lipids, proteins, or nucleic acids.

Carbohydrates

Organic molecules consisting of carbon, hydrogen, and oxygen in a $1:2:1$ ratio (CHO), used for energy and structural materials.

Cellulose

A structural component of plants consisting of glucose chains hydrogen-bonded side by side in tight bundles.

Starch

The main energy reserve in plants, composed of glucose monomers.

Glycogen

An energy reserve polysaccharide in animals, abundant in the liver and muscles.

Lipids

Greasy, oily, or waxy nonpolar organic molecules consisting of CHO, often containing one or more fatty acid tails.

Fatty Acid

Monomer of lipids consisting of a long chain of carbon atoms with an acidic carboxyl group at one end.

Triglyceride

A fat lipid with three fatty acid tails attached to a glycerol backbone.

Phospholipid

The main structural component of cell membranes, composed of a phosphate group, a hydrophilic head, and two nonpolar fatty acid tails.

Lipid Bilayer

A double layer of lipids arranged tail-to-tail that forms the structural foundation of cell membranes.

Waxes

Lipids made of a fatty acid tail and a long-chain alcohol ($-OH$) or carbon rings, forming tightly packed water-repellant structures.

Steroids

Lipids made of $4$ carbon rings with no fatty acid tails that function in the endocrine system.

Proteins

Organic molecules composed of CHON that make up enzymes, antibodies, and structures; composed of amino acid monomers.

Amino Acid

Protein monomer consisting of a small organic compound with a carboxyl group, amine group, and a characteristic side group.

Peptide Bond

A bond between the amine group of one amino acid and the carboxyl group of another.

Polypeptide

A chain of amino acids linked by peptide bonds, representing a protein's primary structure.

Denaturation

Process in which a protein's structure unravels and its function is lost.

Nucleotide

Monomer of nucleic acids containing a five-carbon sugar, nitrogen-containing base, and phosphate groups (CHONP).

Nucleic Acids

Polymers of nucleotides joined by sugar-phosphate bonds that serve as energy carriers, enzyme helpers, chemical messengers, and DNA/RNA subunits.

Buffers

A set of chemicals that keep pH stable by alternately donating and accepting ions.

Enzyme

A molecule that speeds up a reaction without being changed by it.

Metabolism

All enzyme-mediated reactions within cells to acquire and use energy to stay alive, grow, and reproduce.

Cell Theory

States that each organism consists of one or more cells, the cell is the structural/functional unit of organisms, all living cells arise from preexisting cells, and cells contain hereditary material (DNA).

Endomembrane System

A series of interacting organelles between the nucleus and plasma membrane.

Ribosomes

Organelles that build proteins.

Endoplasmic Reticulum (ER)

A continuous system of sacs and tubes extended from the nuclear envelope, occurring as rough ER (with ribosomes) or smooth ER (without ribosomes).

Golgi Body

Organelle that modifies polypeptides and lipids, sorting and packaging finished products into transport vesicles.

Vesicle

Small, membrane-enclosed saclike organelle that stores, transports, or degrades its contents.

Vacuole

A fluid-filled organelle that isolates or disposes of wastes, debris, or toxic materials.

Lysosome

Vesicle containing enzymes for intracellular digestion and breaking down bacteria.

Peroxisome

Enzyme-filled vesicle that breaks down amino acids, fatty acids, and toxic substances.

Mitochondria

Double-membraned organelles that produce ATP.

Chloroplast

Photosynthetic organelle containing chlorophyll found in plant cells.

Cilia

Short hairlike structures projecting from plasma membranes that beat synchronously to stir fluid or propel cells.

Flagella

Long tail-like structure that whips back and forth to propel cells through fluid.