Cell Structure and Function

Active transport

The movement of materials through the cell membrane using energy. Active transport. Active transport is the process where cells use energy to move substances against a concentration gradient.

Cell

The basic unit of life. cell. A cell is the smallest living structure that makes up all organisms and carries out essential life functions.

Cell membrane

The cell boundary that controls what enters and leaves the cell. Cell membrane. The cell membrane is like a gatekeeper that lets important materials in and out of the cell.

Cell theory

Cells make up all organisms, are the basic units of life, and come from other cells. Cell theory. Cell theory states that all living things are made of cells, which are the fundamental unit of life.

Cell wall

The rigid structure around a plant cell that supports and protects it cell wall. A cell wall is a tough outer layer that gives shape and protection to plant cells.

Chloroplast

The plant organelle that uses light energy to make food chloroplast. Chloroplasts are parts of plant cells where photosynthesis happens, turning sunlight into energy.

Cytoplasm

A jellylike material in a cell. Cytoplasm. The cytoplasm is a thick fluid inside a cell that surrounds all the internal structures and helps keep everything in place.

Cytoskeleton

The protein network that controls the cell's shape and movement cytoskeleton. The cytoskeleton is like a cell's framework, giving it shape and helping it move.

Diffusion

The movement of molecules from an area of higher density to an area of lower density. Diffusion is the process where substances spread out evenly in a space.

Endocytosis

A cell taking in a substance by surrounding it with its cell membrane. Endocytosis. It's a process where cells engulf material from their surroundings to bring it inside.

Endoplasmic reticulum

The membranes in a cell's cytoplasm that move proteins endoplasmic reticulum. The endoplasmic reticulum is an organelle in cells that helps produce and transport proteins and lipids.

Eukaryote

A cell that has a membrane and a nucleus. Eukaryote. A eukaryote is an organism whose cells have a nucleus enclosed within a membrane.

Exocytosis

The process by which a cell removes materials through its vesicle is called exocytosis. Exocytosis is when a cell releases substances outside by fusing a vesicle with the cell membrane.

Facilitated diffusion

The transport of materials across the cell membrane by transport proteins. Facilitated diffusion. Facilitated diffusion is a process where transport proteins help move substances across a cell membrane without using energy.

Flagellum

A long, tail-like structure that helps a cell to move. Flagellum. A flagellum is a whip-like appendage that acts like a propeller to help single-celled organisms and some cells move around.

Fluid mosaic model

A model of the cell membrane showing molecules in constant motion. Fluid mosaic model. This model describes the cell membrane as a flexible layer with proteins embedded in or attached to a sea of lipids, allowing movement and fluidity.

Golgi body

The cell structure that packages materials for transport within and out of the cell is the Golgi body. The Golgi body is like the cell's post office, preparing and sending proteins and other materials to their destinations.

Hypertonic solution

A solution with a higher solute concentration than that of cells in that solution. Hypertonic solution. In simple terms, a hypertonic solution will cause cells to lose water and shrink because it has more dissolved substances than inside the cells.

Hypotonic solution

A solution with a lower solute concentration than that of cells in that solution. Hypotonic solution. A hypotonic solution causes cells to swell as water enters through osmosis.

Isotonic solution

A solution with the same solute concentration as the cells it contains. Isotonic solution. An isotonic solution is one where the cell and the surrounding solution have equal concentrations of solutes, preventing water movement that would cause the cell to shrink or swell.

Lysosome

A cell organelle that contains digestive enzymes. Lysosome. It is a small structure in cells that breaks down waste material and debris.

Mitochondrion

The cell organelle that releases energy from food molecules mitochondrion. The mitochondrion is the powerhouse of the cell, converting food into energy.

Nucleolus

The organelle that produces ribosomes in eukaryotic cells, it is inside the nucleus. Nucleolus. The nucleolus is a part of the cell that makes tiny machines called ribosomes, which help build proteins.

Nucleus cell

The control center of a cell. Nucleus. The nucleus is like the cell's brain, controlling growth and activity by holding DNA.

Organelle

A structure in a cell, specialized to perform a specific function. Organelle. An organelle is like a tiny machine inside a cell that helps it do specific jobs.

Osmosis

The diffusion of water through a semipermeable membrane. Osmosis. Osmosis is the movement of water from an area of low solute concentration to an area of high solute concentration through a semipermeable membrane.

Passive transport

The movement of materials through a cell membrane without the use of energy. Passive transport. It is when substances move across a cell membrane naturally, without the cell needing to spend any energy.

Phospholipid

A lipid that contains phosphorus, it makes up cell membranes. Phospholipid. A phospholipid is a special type of fat that forms the protective outer layer of cells.

Phospholipid bilayer

A double-layered sheet of phospholipids that makes up a cell membrane. Phospholipid bilayer. It's like a protective skin for cells, letting some substances in and out while keeping others out.

Prokaryote

A cell without a nucleus and other organelles, like bacteria. Prokaryote. A prokaryote is a simple, single-celled organism that lacks a nucleus.

Ribosome

A small cell structure that builds proteins. Ribosome. A ribosome is like a tiny machine in cells that reads genetic instructions to make proteins.

Selective permeability

The ability of cell membranes to allow some, but not all, substances to pass through selective permeability. Selective permeability means that a cell membrane controls which substances can enter or leave the cell.

Tissue

A group of similar cells working together to perform the same function. Tissue. Tissue is a collection of similar cells that come together to perform a specific job in an organism.

Vacuole

The cell organelle that stores materials. Vacuole. A vacuole is like a storage bag inside a cell that holds water, nutrients, and waste.