The Inner Life of Cells

Objective:1.Review the organelles of a plant and animal cell

2.Review the functions of these organelles3.Review the differences between plant and animal cells and what

functions these differences serve

• BIOLOGY is the scientific study of life in its many forms.

• 1. Grow and develop• 2. Repair • 3. Reproduce• 4. Respond to their environment• 5. Metabolism – are involved in numerous

chemical reactions • 6. Exchange materials with environment

(oxygen & wastes)• 7. Composed of cells (containing large,

complex molecules)

CHARACTERISTICS OF LIFE:

1. Cells are the basic units of life. •Nothing smaller than a cell is alive•Unicellular organism exhibits the characteristics of life 2. All living organisms are composed of cells.•Multicellular organisms (ie: animals) are made of tissues composed of cells eg. blood, nerves, cartilage, muscle and bone are made up of cells•These cells perform all the functions required for life 3. New cells arise only from pre-existing cells.•Life depends on cells (cells divide and pass on the information of inheritance in their DNA)

CELL THEORY:

Cells vary in shape & size depending on their function

CELL SIZE & SHAPE:

Basic Cell Structure

• All cells have these 5 basic structures:

1)Cell/Plasma membrane2)Nucleus3)Nucleolus4)Nuclear Envelop5)Cytoplasm

1) Plasma Membrane • Surrounds cell and organizes it into

various compartments inside• about 10 nm in thickness • its function is to form a boundary

that surrounds the cell, keeps it intact, and regulates what enters and exits the cell

CELLULAR ORGANIZATION:

2) Nucleus (command centre)• large, centrally located structure • about 5 um in diameter• its function is to determine the

structural features of the cell and to control its metabolic reactions – (how the cell looks and functions)

CELLULAR ORGANIZATION: (cont’d)

The Nucleus

Contains:•DNA•Chromosomes•Nuclear Envelope•Nucleolus

3. Nucleolus• a dark, granular region inside

the nucleus• a cell may have more than one• contains RNA (ribonucleic acid)• its function is to produce and store

the subunits of ribosomes which are made up of ribosomal RNA (rRNA).

4. Nuclear envelope• a double membrane surrounding the

nucleus which contains nuclear pores (tiny holes)

• its function is to control the passage of molecules between the nucleus and the cytoplasm

The Nucleus

5) Cytoplasm• is the portion of the cell between the

nucleus and the plasma membrane• it contains water, nutrient molecules, gases

such as oxygen and carbon dioxide, and wastes

• organelles are tiny structures found in the cytoplasm that each perform a specific function

• the cytoskeleton is a network of fibres found throughout the cytoplasm which functions to maintain the cell’s shape and allow the cell and its contents to move

CELLULAR ORGANIZATION: (cont’d)

Comparing Plant and Animal Cells

• …however, not all cells contain all the same structures.

• Complete the table I have given you by filling in the functions and drawing a diagram of each organelle listed. Indicate whether each organelle is found in a plant cell, and animal cell, or both cells.

• When you have finished, answer the questions on the back of the sheet.

Homework…• You are to answer questions 1-5 on page 20 of

your handout.• There will be a quiz based on tonight’s homework

TOMORROW.• Show animation!!!

We will be learning about the 4 macromolecules of life (carbohydrates, lipids, proteins and nucleic acids) as well as methods of passive and active transport across the cell’s plasma membrane.