GAP Ch3: Cells

Cell

The smallest structural and functional unit of an organism.

Cell Membrane

Also known as the plasma membrane, it separates the intracellular contents from the extracellular environment.

Somatic Cells

All cells in the body other than sperm and egg cells; diploid with 46 chromosomes.

Diploid

Having two sets of chromosomes, one inherited from each parent, totaling 46 in humans.

Intracellular

Refers to the area or environment inside a cell.

Extracellular

Refers to the area or environment outside a cell.

Phospholipid Bilayer

A double layer of phospholipids that makes up the cell membrane.

Hydrophilic Head

The water-loving part of a phospholipid that is negatively charged.

Hydrophobic Tails

The water-fearing, nonpolar part of a phospholipid.

Integral Proteins

Proteins that span the lipid bilayer of the cell membrane.

Peripheral Proteins

Proteins that are positioned on the inner or outer surface of the cell membrane.

Selective Permeability

The ability of the cell membrane to regulate what enters and exits the cell.

Passive Transport

Movement of substances across the membrane without using energy.

Active Transport

Movement of substances across the membrane using energy (ATP).

Diffusion

The movement of particles from an area of high concentration to an area of low concentration.

Facilitated Diffusion

A process where substances move across the membrane with the help of transport proteins.

Osmosis

The diffusion of water across a semipermeable membrane.

Hypertonic Solution

A solution with a higher concentration of solutes outside the cell, causing it to lose water.

Isotonic Solution

A solution with the same concentration of solutes inside and outside the cell, maintaining cell shape.

Hypotonic Solution

A solution with a lower concentration of solutes outside the cell, causing it to gain water and potentially burst.

Lysis

The process of a cell breaking apart, typically due to excessive water intake.

Filtration

The movement of fluid from a high pressure area to a low pressure area.

Endocytosis

The process of moving materials into the cell.

Phagocytosis

A form of endocytosis where large particles are engulfed by the cell.

Pinocytosis

A form of endocytosis where the cell ingests fluids and dissolved substances.

Receptor Mediated Endocytosis

Endocytosis that involves specific receptors for selective uptake of substances.

Exocytosis

The process of exporting particles or substances out of the cell.

Cytosol

The jelly-like substance within the cell where biochemical reactions occur.

Organelle

Membrane-enclosed structures in the cell that perform unique functions.

Golgi Apparatus

An organelle responsible for sorting, modifying, and shipping proteins.

Mitochondria

Known as the powerhouse of the cell, involved in ATP production.

Peroxisome

An organelle involved in lipid metabolism and detoxification.

Cytoskeleton

The supportive structures of the cell, includes microtubules, microfilaments, and intermediate filaments.

Chromatin

Thread-like material in the nucleus composed of DNA and proteins.

Nucleus

The control center of the cell that stores genetic material (DNA).

Gene

A functional segment of DNA that provides the information to make proteins.

Transcription

The process of synthesizing mRNA from a DNA template.

Translation

The process of forming a protein from mRNA at the ribosome.

Cell Cycle

The sequence of events from the creation of a cell to its division.

Interphase

The phase of the cell cycle when the cell is not dividing.

Mitosis

The process of cell division that produces two identical daughter cells.

Prophase

The first stage of mitosis where chromatin condenses into chromosomes.

Metaphase

The second stage of mitosis where sister chromatids align in the middle of the cell.

Anaphase

The third stage of mitosis where sister chromatids are pulled apart to opposite ends.

Telophase

The final stage of mitosis where two new nuclei form around the separated chromatids.

Cytokinesis

The division of the cytoplasm that occurs immediately after mitosis.

S Phase

The phase of interphase where DNA replication occurs.

Cleavage Furrow

The contractile band in the cell that forms during cytokinesis.

Sister Chromatids

Identical copies of a chromosome, joined together at the centromere.

Hydrostatic Pressure

Pressure exerted by a fluid in a confined space, involved in filtration.

ATP (Adenosine Triphosphate)

The energy currency of the cell, used in active transport and energy-requiring processes.

Lock and Key Model

Describes how enzymes bind to specific substrates for catalyzing reactions.