Chapter 3: Cells

Flashcards for Cell Biology Exam 1 Review

Nucleus

The control center of the cell, containing the cell's DNA.

Cytoplasm

The gel-like substance within the cell that contains organelles.

Cell (Plasma) Membrane

The outer boundary of the cell, composed of a phospholipid bilayer with embedded proteins.

Selective Permeability

The ability of the plasma membrane to regulate the passage of substances into and out of the cell.

Cholesterol

A lipid molecule that helps stabilize the plasma membrane.

Membrane Proteins

Proteins embedded in the plasma membrane that perform various functions, such as transport and signaling.

Carbohydrates

Sugars attached to the surface of the plasma membrane, involved in cell recognition and signaling.

Cellular Adhesion Molecules (CAMs)

Proteins on the cell surface that facilitate cell-to-cell interactions.

cytoplasm

the “liquid” that supports and maintains cell shape

Ribosomes

Sites of protein synthesis.

Endoplasmic Reticulum (ER)

A network of membranes involved in protein and lipid synthesis.

Smooth ER

enzymes that are important in synthesizing lipids, absorbing fats, and breaking down certain drugs

Rough ER

Move through ER tubules where they fold into their characteristic 3D shapes

Golgi Apparatus

Modifies, sorts, and packages proteins and lipids.

Vesicles

Small, membrane-bound sacs that transport substances within the cell.

Mitochondria

The powerhouses of the cell, responsible for ATP production.

Lysosomes

Organelles containing enzymes that break down cellular waste.

Peroxisomes

Organelles containing enzymes that detoxify harmful substances.

Cytoskeleton

A network of protein fibers that provides structural support and facilitates movement.

Microfilaments

Rods of protein actin that form meshworks to provide cellular mobility

Microtubules

Long thin tubes hollow rod of the protein tubulin that aid in shape

Intermediate filaments

Aids in crossection between microtubules and microfilaments also help form protective layer

Centrosome

A structure involved in cell division, containing centrioles.

Centrioles

Produce external parts cilia and flagella

Cilia

Short, hair-like appendages that move substances across the cell surface.

Flagella

Long, whip-like appendages that enable cell motility.

Nuclear Envelope

The double membrane surrounding the nucleus.

Nucleolus

A structure within the nucleus where ribosomes are assembled.

Chromatin

The genetic material of the cell, consisting of DNA and proteins.

Passive Transport

Movement of substances across the cell membrane without the use of energy.

Diffusion

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

Facilitated Diffusion

Diffusion with the help of membrane proteins.

Osmosis

The movement of water across a selectively permeable membrane from an area of high water concentration to an area of low water concentration.

Filtration

The movement of water and small solutes across the cell membrane due to pressure.

Osmotic Pressure

The potential pressure of a solution to draw water into it by osmosis.

Isotonic Solution

A solution with the same osmotic pressure as the cell.

Hypertonic Solution

A solution with a higher osmotic pressure than the cell.

Hypotonic Solution

A solution with a lower osmotic pressure than the cell.

Active Transport

Movement of substances across the cell membrane that requires energy (ATP).

Endocytosis

The process by which cells engulf substances from their surroundings.

Exocytosis

The process by which cells release substances into their surroundings.

Transcytosis

A combination of endocytosis and exocytosis to rapidly transport substances across a cell.

Pinocytosis

Cell drinking; the uptake of small droplets of fluid.

Phagocytosis

Cell eating; the uptake of large particles or cells.

Receptor-Mediated Endocytosis

Endocytosis that requires a receptor to bind to a specific molecule.

Cell Cycle

Three steps : interphase, mitosis, and cytokinesis

Interphase

The resting phase of the cell cycle, during which the cell grows and prepares for division.

Mitosis

The process of cell division that results in two identical daughter cells.

Cytokinesis

The division of the cytoplasm following mitosis.

Contact Inhibition

The tendency of cells to stop dividing when they come into contact with each other.

Tumor

A mass of abnormal cells that results from uncontrolled cell division.

Oncogenes

Genes that promote cell growth and division. When mutated, they can cause cancer.

Benign tumor

Lump, normally doesn’t spread

Malignant tumor

Invasive, aggressive and will spread

Tumor Suppressor Genes

Genes that inhibit cell growth and division. When inactivated, they can lead to cancer.

Stem Cells

Undifferentiated cells that can develop into specialized cells.

Progenitor Cells

Cells that are partially differentiated and can only develop into a limited number of cell types.

Totipotent Cells

Cells that can develop into any cell type in the body, including the placenta.

Pluripotent Cells

Cells that can develop into any cell type in the body, except for the placenta.

Apoptosis

Programmed cell death that is a normal part of development.

Necrosis

Cell death due to injury or disease.