Image taken from: http://en.wikipedia.org/wiki/Eukaryotic
(06-09-06)
SCE ‘HIGHER’ HUMAN BIOLOGY
UNIT D04312 (1 CREDIT)
CELL FUNCTION & INHERITANCE
MOIRA CURRIE
© 2008 MORAY COLLEGE
PACK 1
CELL STRUCTURE AND FUNCTION
OBJECTIVES
At the end of this unit you should be able to:
1. Describe the structure of a typical animal cell.
2. Describe the shape and ascribe function to the following cell organelles and be
able to recognise them from electron micrographs.
 Mitochondria
 Lysosomes
 Rough E.R.
 Smooth E.R.
 Golgi Body
 Nucleus
 Ribosomes
 Centrioles
Describe the structure of the cell membrane.
Briefly describe the main features of the main tissue groups of the body.
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PACK 1
CELL STRUCTURE AND FUNCTION
Cells are the building blocks of all life forms. Each human being is composed of trillions
of these cells and although many cells are specialised and have unique functions, they
are all put together in roughly the same way.
Today our understanding of the cell provides us with 4 concepts which together make
up the Cell Theory.
1.
A cell is the basic structural and functional unit of life.
2.
The activity of an organism depends on the individual and collective activities of
its component cells.
3.
The biochemical processes of life are determined and made possible by the
specific subcellular components (organelles) which those cells contain.
4.
Cells can only arise as divisions of pre-existing cells.
Text Book – Higher Human Biology. James Torrance
Read text book page 25. This shows a diagram of a “typical” cell.
Search through the index of the text to find information on the
following organelles:
Ribsosomes; Mitochondria; Golgi Body; Smooth Endoplasmic Reticulum; Rough
Endoplasmic Reticulum; Lysosomes; Centrioles; Nucleolus; Nucleolus; Nucleus; Plasma
Membrane.
Each cell can be thought of as a small “factory” making an end product. Each of these
cell organelles corresponds to an area in a factory making any end product such as
biscuits.
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ACTIVITY
Make up your own notes to cover the structure and
function of each of these organelles.
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ACTIVITY SAQ 1
Complete the table below
Organelle
Function
Mitochondrion
Nucleolus
Golgi Body
Smooth Endoplasmic Reticulum
Rough Endoplasmic Reticulum
Centrioles
Lysosomes
Ribosomes
Plasma Membrane
Nucleus
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SIZE UNITS
Many cells are extremely tiny. A human red blood cell for example is only 8 one
thousandths of a millimetre in diameter!
Trying to work with such small units is not easy and so SI Units are used. (SI =
Systeme Internationale)
The SI Unit of length is the METRE (m)
1cm
1mm
1µ
1nm
=
=
=
=
1/100m
1/1,00m
1/1,000,000m
1/1,000,000,000m
=
=
=
=
10-2m
10-3m
10-6m
10-9m
(µ
=
(nm =
micrometer)
nanometre)
By dividing or multiplying by 10 or 100 or 1,000 you can change one unit to another.
ACTIVITY
SAQ2
Try the following:
1.
The cell membrane is 8nm wide. Convert this to millimetres.
2.
The biggest cell in the human body is nearly 100,000 nm in diameter. Express
this as micrometers.
3.
A Typical human cell is almost 0.01 mm in diameter. Express this as
micrometers.
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Have a look on the internet to find these different types of human cells
Skeletal muscle
Red Blood cells
White blood cells
Articular Cartilage
Nerve tissue
Smooth muscle
Bone
Simple Epithelium
Compound Epithelium
Adipose
White Fibrous
Yellow Elastic
A very good book to have a look through is “Cell and Tissue Ultrastructure” by P.
Cross and K. Mercer. Publisher - Freeman. This is in the Library 574.872CRO cl.
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ANSWERS TO SAQ 1
Organelle
Function
Mitochondrion
Site of Aerobic Respiration and Energy
(ATP) production.
Nucleolus
Site of RNA production - the intermediate
between proteins and DNA.
Golgi Body
Packages proteins ready for internal or
external transport.
Smooth Endoplasmic Reticulum
Synthesis and transport of Lipids
Rough Endoplasmic Reticulum
Transport of Proteins. Rough effect due
to Ribosomes.
Centrioles
Microtubules which assist in cell division.
Lysosomes
Contain autolytic enzymes which break
down damaged cells.
Ribosomes
Synthesis of Proteins from amino acids
using instructions coded in DNA and using
RNA as an intermediary.
Plasma Membrane
Limit of cell. Controls the transport of
materials into and out of the cell.
Nucleus
Contains coded instructions in the form of
Deoxyribonucleic. Acid for the synthesis
of proteins. These in turn determine the
structure and function of the organism.
SAQ 2
1. 8n = 0.000008mm
2. 100,000n = 100µ
3. 0.01mm = 10µ
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