Biology: AOS1 (Chapters 1, 2 & 3)

A comprehensive set of biology flashcards covering essential terms and concepts from Chapters 1, 2, and 3.

Abiotic

Not living.

Biotic

Living; made up of at least one cell.

Cell theory

The theory that living things are made up of at least one cell, and that these cells are the basic unit of life and came from pre-existing cells.

Cell wall

A structure that surrounds a plant cell and provides support and protection.

Chloroplast

An organelle where photosynthesis occurs; contains chlorophyll.

Cilia

Short microtubules projecting from a cell that move to provide motility or movement of fluid.

Cytoplasm

All the contents inside the membrane of a cell, except the nucleus; includes cytosol and organelles.

Cytosol

The liquid inside a cell, between the organelles (not including the organelles).

Endosymbiosis

Symbiosis where one organism lives inside another.

Eukaryote

A single-celled or multicellular organism whose cells include membrane-bound organelles; includes protists, fungi, plants, and animals.

Flagella

Long microtubules projecting from a cell that move to provide motility or movement of fluid.

Fluid mosaic model

A model that represents the plasma membrane as a combination of phospholipids, proteins, cholesterol, and carbohydrates that gives the membrane its fluid nature.

Golgi apparatus

An organelle consisting of layers that modifies and packages proteins.

Hydrophilic

Dissolves easily in water; also called lipophobic.

Hydrophobic

Does not dissolve readily in water; also called lipophilic.

Lysosome

An organelle containing enzymes that break down foreign matter or materials no longer required.

Mitochondrion

An organelle where stages of aerobic respiration occur, releasing energy (ATP).

Multicellular

Made up of more than one cell.

Nucleoid

An irregularly shaped area in a prokaryote where the genetic material is located.

Nucleus

A double-membrane bound organelle that contains genetic material (DNA, RNA).

Organelle

A compartment within a cell that performs specific functions.

Organism

An individual that is living (biotic).

Plasma membrane

A membrane made up of two layers of phospholipids that encloses the contents of a cell.

Prokaryote

A single-celled organism that does not have membrane-bound organelles; includes bacteria and archaea.

Ribosome

A non-membrane-bound organelle involved in the synthesis of proteins.

Rough endoplasmic reticulum

An organelle that transports proteins in vesicles to the Golgi apparatus.

Semi-permeable membrane

A membrane that only lets certain substances cross it; also called partially permeable.

Smooth endoplasmic reticulum

An organelle that synthesizes and transports lipids.

Symbiosis

A beneficial relationship between two organisms.

Unicellular

Made up of only one cell.

Vacuole

An organelle that stores substances; important in maintaining the structure of plant cells.

Vesicle

An organelle that transports materials between organelles and within the cell.

Active transport

The net movement of a substance from a region of low concentration to a region of high concentration using a protein carrier and requiring energy input.

ADP (adenosine diphosphate)

A compound composed of adenosine and two phosphate groups that can store energy when another phosphate group is added, forming ATP.

Aerobic cellular respiration

Cellular respiration that occurs in the presence of oxygen and involves the transformation of the chemical energy in glucose into ATP.

Anaerobic cellular respiration

Cellular respiration that occurs in the absence of oxygen and involves the transformation of the chemical energy in glucose into ATP; also known as fermentation.

ATP (adenosine triphosphate)

The main immediate source of chemical energy in a cell, powering most cellular processes.

Autotroph

An organism that synthesizes its own organic materials (food), using energy from its physical environment.

Bulk transport

The movement of large particles across the plasma membrane, requiring the input of energy (ATP).

Carrier protein

A transmembrane protein that binds to a specific substance and changes shape to move that substance across the plasma membrane.

Cellular respiration

A chemical reaction in which glucose is broken down to form carbon dioxide and water, with energy in the form of ATP.

Channel protein

A transmembrane protein that allows hydrophilic substances to move across the plasma membrane.

Chemical energy

Energy from organic molecules in food.

Chlorophyll

The pigment in chloroplasts that absorbs light energy for photosynthesis.

Concentration gradient

The difference between the concentrations of a substance in two regions.

Crenation

The shrinkage of a cell that occurs when there is net movement of water out of the cell in a hypertonic solution.

Cristae

The highly folded inner membrane of the mitochondria, site of the electron transport chain.

Endocytosis

The movement of large particles into the cell without crossing the plasma membrane directly, using vesicles and ATP.

Exocytosis

The movement of large particles out of the cell using vesicles and ATP.

Facilitated diffusion

The passive movement of a substance from a region of high concentration to low concentration with assistance from proteins.

Fermentation

The process by which one molecule of glucose is broken down without oxygen to produce ATP.

Flaccid

Refers to a plant cell that is limp due to lack of water.

Glycolysis

The first stage of cellular respiration, breaking down glucose into two pyruvate molecules.

Grana

Stacks of thylakoid membranes where the light-dependent stage of photosynthesis occurs.

Haemolysis

The rupture of a red blood cell due to net movement of water into the cell.

Heterotroph

An organism that ingests organic materials from other organisms for energy.

Hypertonic

A solution with a higher solute concentration than the cell's internal environment.

Hypotonic

A solution with a lower solute concentration than the cell's internal environment.

Isotonic

A solution with the same solute concentration as the cell's internal environment.

Light energy

Energy from the sun.

Lipophilic

Dissolves easily in lipids; also called hydrophobic.

Lipophobic

Does not dissolve readily in lipids; also called hydrophilic.

Matrix

The fluid component of the mitochondria and the site of the Krebs cycle.

Osmosis

The net passive movement of free water across a semi-permeable membrane.

Passive transport

The movement of a substance from a region of high concentration to low concentration without energy input.

Phagocytosis

A type of endocytosis in which a solid substance enters a cell by vesicle-mediated transport.

Photosynthesis

The process of converting light energy into chemical energy in glucose.

Pinocytosis

A type of endocytosis in which liquid or dissolved substances enter a cell by vesicle-mediated transport.

Plasmolysis

The contraction of the plasma membrane away from the cell wall in a hypertonic solution.

Polar

Describes a molecule with different charged sides; dissolves in water.

Protein-mediated transport

When a protein assists in the transport of a substance across a plasma membrane.

Semi-permeable

Allowing some substances to pass while preventing others.

Simple diffusion

The passive movement of a substance from high to low concentration until equilibrium.

Sodium-potassium pump

The exchange of sodium and potassium ions across the plasma membrane of a cell.

Stroma

Gel-like fluid inside a chloroplast that surrounds grana.

Surface area

The area exposed to the external environment.

Surface area to volume ratio (SA:V)

The relationship between the surface area of a cell and its volume.

Thylakoid membranes

Membranes inside chloroplasts that contain chlorophyll.

Tonicity

How solute concentration determines the direction and rate of osmosis.

Turgid

Refers to a plant cell swollen with water in a hypotonic solution.

Vesicle-mediated transport

The movement of substances across the plasma membrane using vesicles.

Volume

The amount of space inside an object.

Adult stem cells

Undifferentiated cells found in specific tissues throughout life.

Anaphase

A mitotic phase where double chromosomes separate.

Angiogenesis

The formation of new blood vessels.

Apoptosis

The controlled death of cells as part of development.

Apoptotic bodies

Vesicles containing intracellular contents of a dying cell.

Benign

Not cancerous; will not spread.

Binary fission

A type of asexual reproduction in prokaryotic cells.

Blastocyst

A stage of embryonic development with some differentiation.

Bleb

A rounded structure forming on a cell undergoing apoptosis.

C (cytokinesis) phase

The portion of the cell cycle that includes cytokinesis.

Cancer

A disease resulting from uncontrolled division of abnormal cells.

Caspases

Protease enzymes that cleave proteins to trigger cell death.

Cell cycle checkpoints

Control points within the cell cycle that ensure accurate division.

Cell plate

A structure that forms during cytokinesis in plant cells.

Centromere

The structure in a chromosome where two chromatids are held together.

Centrosome

An organelle where spindle microtubules develop during cell division.

Chromatid

One of two strands of a double chromosome formed before division.

Chromatin

Condensed structure of DNA and protein in the nucleus.