Life Science Chapter 2 Vocabulary

Science

Organelle

The usually membrane-surrounded structures in a eukaryotic cell that perform special functions

Cell Membrane

The structure that surrounds all cells and regulates what comes in and out.

Cell wall

a rigid structure that surrounds and protects some cells

Capsule

a slimy layer surrounding some bacteria that protects them from harmful substances and prevents their drying out

Flagellum

a whip-like structure that some cells use to propel themselves through their environment

DNA

the molecule that contains important information for making proteins and helps regulate many cellular processes.

Chromosomes

a structure that contains a cell’s DNA

Endoplasmic Reticulum or ER

A network of tubes that help produce and transport proteins and other molecules through the cell.

Golgi apparatus

This organelle modifies many of these proteins and packages them into vesicles.

Ribosomes

Small structures that assemble proteins.

cytoskeleton

Consists of several types of long, thin fibers anchored to various parts of the cell that help it maintain and change its shape

Lysosomes

Small organelles that act as the demolition crews of the cell.

Enzymes

Proteins that speed up or slow down chemical reactions.

Mitochondrion

Makes most of the cell’s ATP, which is used to power cellular processes.

Selectively Permeable

It allows some substances to pass through but keeps others out.

Concentration gradient

When a certain type of molecule is more densely packed on one side of the membrane then on the other.

Diffusion

The movement of molecules though a membrane is called diffusion.

Osmosis

This movement of water across a semipermeable membrane

Passive transport

the movement of molecules across a membrane without the cell doing any work, as in osmosis and diffusion.

Active transport

the movement of molecules across a membrane that requires the cell to do work.

Cytoplasm

The material inside of a cell excluding the nucleus.

Cell theory

The model of the cell that states that cells make up all living things, come from preexisting cells and perform the functions of living things.

Tissue

A group of similar cells that work together

organ

A group of tissues that work together

producer

An organism that can make its own food, typically through photosynthesis

photosynthesis

The process by which plant uses energy from the sun to turn carbon dioxide and water into the sugar glucose.

chlorophyll

The green pigment that absorbs sunlight for photosynthesis

ATP

the molecule that a cell uses to power many processes in the cell that need chemical energy

cellular respiration

The process of breaking down molecules to produce ATP is called Cellular respiration.

anaerobic

describes a process that does not use oxygen

Stem cell

a special cell that divides and matures into any type of cell needed by the body