Biology Lecture Review Flashcards

Comprehensive vocabulary flashcards covering life characteristics, cell theory, biological organization, viruses, macromolecules, enzymes, and experimental design.

Homeostasis

The process of maintaining a stable internal environment within an organism.

Growth and Development

An organism's increase in size and/or change over time.

Evolution

Changes in inherited traits within populations over generations.

Abiotic Factors

Nonliving environmental factors such as temperature, water, sunlight, pH, and salinity.

Biotic Components

Living or once-living parts of an environment, including plants, animals, bacteria, fungi, and dead leaves.

Biological Hierarchy

The structural organization of life from smallest to largest: atom $\rightarrow$ molecule $\rightarrow$ organelle $\rightarrow$ cell $\rightarrow$ tissue $\rightarrow$ organ $\rightarrow$ organ system $\rightarrow$ organism.

Robert Hook

The scientist who observed cork and introduced the term cell.

Matthias Schleiden

The scientist who concluded that all plants are made of cells.

Theodor Schwann

The scientist who concluded that all animals are made of cells.

Rudolf Virchow

The scientist who observed cells dividing and stated that new cells come from pre-existing cells.

Cell Theory

The fundamental biological principle stating that all living things are made of one or more cells, the cell is the basic unit of life, and new cells arise from existing cells.

Organelles

Small structures inside cells that perform specialized biological jobs.

Virus

An acellular particle containing genetic material surrounded by a protein coat that cannot reproduce independently without a host cell.

Monosaccharide

The basic building block (monomer) of carbohydrates.

Glucose

A monosaccharide produced in photosynthesis that serves as the quickest form of energy.

Triglyceride

A lipid molecule composed of glycerol and $3$ fatty acids.

Phospholipid

A hydrophobic lipid that serves as a major component of cell membranes.

Amino Acid

The basic building block (monomer) of proteins.

Denaturation

A process caused by extreme heat or pH that alters the three-dimensional shape and active site of a protein or enzyme, disabling its function.

Nucleotide

The building block (monomer) of nucleic acids.

DNA

A nucleic acid that stores hereditary information and contains the nitrogenous bases A, T, C, and G.

RNA

A nucleic acid that helps cells use genetic information to make proteins and contains the nitrogenous bases A, U, C, and G.

Enzyme

A biological catalyst that speeds up chemical reactions by lowering the activation energy needed.

Substrate

The specific reactant substance upon which an enzyme acts.

Active Site

The specific region on an enzyme where the substrate binds.

Activation Energy

The minimum energy needed to initiate a chemical reaction, which is reduced by enzymes.

Independent Variable

The variable deliberately changed by a scientist in an experiment, which is plotted on the $x$-axis of a graph.

Dependent Variable

The variable measured in an experiment to evaluate the effect of the independent variable.

Constants

Experimental variables that are deliberately kept the same throughout an investigation.

Hypothesis

A testable prediction formulated before conducting an experiment.

Homeostasis

Maintaining a stable internal environment in an organism.

Growth and development

An organism's increase in size and/or change over time.

Reproduction

The process of producing new organisms.

Evolution

Changes in inherited traits within populations over generations.

Abiotic factors

Nonliving environmental factors, such as temperature, water, sunlight, pH, and salinity.

Biotic components

Living or once-living parts of an ecosystem, such as plants, animals, bacteria, fungi, and dead leaves.

Biological hierarchy

The structural levels of organization from smallest to largest: atom, molecule, organelle, cell, tissue, organ, organ system, organism.

Robert Hook

The scientist who observed cork and used the term cell.

Matthias Schleiden

The scientist who concluded that plants are made of cells.

Theodor Schwann

The scientist who concluded that animals are made of cells.

Rudolf Virchow

The scientist who stated that new cells come from pre-existing cells after observing cells dividing.

Cell theory

The unifying theory stating that all living things are made of one or more cells, the cell is the basic unit of life, and new cells arise from other cells.

Organelle

A small structure inside cells that performs specialized jobs.

Virus

An acellular particle containing genetic material surrounded by a protein coat that lacks independent reproduction and homeostasis, requiring a host cell to reproduce.

Carbohydrates

Macromolecules made of monosaccharides that serve as major sources for quick/short-term energy and structural support.

Monosaccharide

The basic building block or monomer of carbohydrates.

Glucose

The quickest form of energy, which is produced during photosynthesis.

Lipids

Mostly hydrophobic macromolecules made of glycerol and fatty acids, whose major functions include long-term energy storage, insulation, membranes, and cushioning of major organs.

Triglyceride

A lipid molecule composed of glycerol and 3 fatty acids.

Phospholipids

Lipid molecules that serve as major components of the cell membrane.

Proteins

Macromolecules built from amino acids whose specialized functions strongly depend on their three-dimensional shape.

Amino acid

The basic building block or monomer of a protein.

Denaturation

The process caused by extreme heat or pH that changes a protein's or enzyme's three-dimensional shape and active site, altering its function.

Nucleic acids

Macromolecules composed of nucleotides that are directly associated with storing and using genetic or hereditary information.

Nucleotide

The monomer or building block of nucleic acids.

DNA

A nucleic acid containing the bases A, T, C, and G that stores hereditary information.

RNA

A nucleic acid containing the bases A, U, C, and G that helps cells use genetic information to make proteins.

Enzyme

A biological catalyst that speeds up chemical reactions by lowering the activation energy needed, remaining unchanged during the reaction.

Activation energy

The energy needed to start a chemical reaction, which is lowered by enzymes.

Substrate

The specific chemical substance that an enzyme acts upon.

Active site

The specific region on an enzyme where the substrate binds.

Optimal range

The specific range of temperature or pH in which an enzyme works best.

Plateau

The point where reaction rate levels off as concentration increases because all available enzyme active sites become occupied.

Independent variable

The variable deliberately changed by a scientist in an experiment, placed on the x-axis of a graph.

Dependent variable

The variable measured during an experiment, placed on the y-axis of a graph.

Constants

Variables that are kept the same during an experiment (also referred to as controlled variables).

Hypothesis

A testable prediction formulated for an experiment.