Cell Structure & Function

Cell Theory• There are three main

elements

• 1. All living things are made up of cells.

• 2. Cells are the smallest working units of all living things.

• 3. All cells come from preexisting cells through cell division.

Definition of Cell

A cell is the smallest unit that is capable of performing life functions.

Examples of Cells

Amoeba

Plant Stem

Red Blood Cell

Nerve Cell

Bacteria

Label your diagram first & then colour it in.

Two Types of Cells

•Prokaryotic

•Eukaryotic

Prokaryotic

• Do not have structures surrounded by membranes.

• Few internal structures.

• One-celled organisms e.g. Bacteria.

More prokaryotic cells

Eukaryotic• Contain organelles surrounded by membranes.• Most living organisms.

Plant Animal

10

“Typical” Animal Cells

11

“Typical” Plant Cell

Common features of all cells

(organelles)

Cell Parts

Cell Membrane

• Outer membrane of cell that controls movement in and out of the cell.

• It is like a big plastic bag with lots of tiny holes.

Nucleus • Acts like the ‘brain’ of the cell.

• Separated from cytoplasm by nuclear membrane.

• Contains genetic material - DNA.

Cytoplasm

• Gel-like mixture.• Surrounded by cell membrane.• Contains hereditary material.

Endoplasmic Reticulum

• Acts as the ‘packaging system’ of the cell.

• Smooth type: lacks ribosomes.

• Rough type: ribosomes embedded in surface.

Ribosomes

• Each cell contains thousands.• Protein builders of the cell.• Can be found floating throughout the cell or

attached to the E.R.

Mitochondria• Known as the ‘powerhouse’

of the cell.• Acts like the digestive

system in that they take in nutrients, break them down and create energy for the cell.

• Most of the chemical reactions involved in cellular respiration happen here.

Golgi Apparatus

• A series of membranes shaped like pancakes.

• Protein 'packaging plant'.

Lysosome• Digestive 'factory' for proteins, fats and

carbohydrates.• The hold enzymes created by the cell.• Cell breaks down

if lysosome explodes.

Vacuoles

• Membrane-bound sacs for storage, digestion, and waste removal.

• Plants also use it to store water.

• In plant cells, they are much larger.