4a: Cell Structure and Function

Describe the functions of cell organelles

Identify organelles on a diagram

Compare and contrast plant and animal cells

Cells

Cells are the basic building block of life. It is the smallest unit at which life can exist.

Cells come in a variety of shapes and sizes with many

specialized functions.

Nerve cells

Paramecium

Red blood cells

Leaf cells

All cells have:

Cell Membrane – separates cell from external environment, regulates flow of materials in and out of the cell.

Cell Wall (Plants only) – Rigid structure surrounding the cell membrane, provides support.

Cytoplasm – jelly like fluid that contains all organelles and important substances like water and sugar.

Genetic Material – instructions for the cell (usually DNA)

Organelles – Special structures that carry out specific roles in the cell

Cell membrane

Mitochondria

Provide energy for the cell by

converting sugar (glucose) into

energy

Chemical reactions take place

on the folds of the inner surface

of the mitochondrion.

Chloroplast (Plants only)

Specialized pigments trap use

energy from the sun to change

carbon dioxide and water into

oxygen and sugar (glucose)

This process is called photosynthesis

Give plants their characteristic green

colour

Ribosomes

Small organelles with no membrane

May be floating in the cytoplasm or attached to the endoplasmic

reticulum (ER)

Used to make proteins

Ribosomes on the ER

Endoplasmic Reticulum

Network of membrane covered channels in a cell

Acts as a transport system for materials made in the cell

May have ribosomes attached at surface

Vesicles

Membrane covered sacs used for transport

May carry products made in the cell such as proteins or enzymes

Vacuoles

Larger membrane covered sac

Used for storage of water and other

materials in a cell

Plant cells usually have a large central

vacuole

Golgi Body

Sorts and packages proteins for transport

Nucleus

Controls all of the cells activities

Contains DNA

Surrounded by the nuclear membrane which has nuclear pores to

allow certain molecules in and out

Nucleolus is the region of the nucleus where ribosomes are made

Animal Cell

Text page 122

Plant Cell

Text page 123

Inner Life of a Cell

http://www.xvivo.net/animation/the-inner-life-of-the-cell/