The Inner Life of Cells
Objective:
1. Review the organelles of a plant and animal cell
2. Review the functions of these organelles
3. 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.
CHARACTERISTICS OF LIFE:
• 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)
CELL THEORY:
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 SIZE & SHAPE:
Cells vary in shape & size depending on their function
Basic Cell Structure
• All cells have these 5 basic
structures:
1) Cell/Plasma membrane
2) Nucleus
3) Nucleolus
4) Nuclear Envelop
5) Cytoplasm
CELLULAR ORGANIZATION:
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: (cont’d)
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)
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
CELLULAR ORGANIZATION: (cont’d)
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
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.