The structure of the cell membrane

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Distance Learning Centre

Organisation of the Body

TAQ 1: Compile a table to compare and contrast light and electron microscopes in terms of how they work, their use, their clarity, and what is meant by the terms resolution or magnification.

Microscopes Type



How they work

Electron Microscope uses electrons to scan small objects requiring magnification to view the image and details of an object.

Light Microscopes use a light source that works with an ocular lens that magnifies the image of an object.

Their use

The use of electrons to magnify small objects

The use of light to identify objects


The clarity of image through an electron microscope is proven to be a lot clearer and sharper.

The clarity of image through a light microscope is not as clear and defined as apposed to an Electronic microscope.


Magnification through an electron microscope is a vast improvement from the human eye, As electrons are a form of power these can be magnified and the visibility of an image or object is improved through an electronic microscope.

Magnification through a light microscope is an improvement from the human eye, however still a resulting process of magnification as appose to if you where required to view the granular detail of an image or object.


Resolution through an electronic microscope is proven to be highly effective. As this type of microscope is used to discover fine and view attention to detail.

Lower resolution through a light microscope is an improvement from human eye, however details can be very basic.

WORD COUNT: 200 words (total) 220

TAQ 2:

a) Label each part of the cell indicated in Appendix 1 Organisation of the body

2.1 Identify and give functions of cell organelles.

S = Cytoplasm

T = Ribosomes

U = Cell membrane

V = Lysosome

W = Endoplasmic reticulum

X= Mitochondrion

Y= Chromatin

Z= Golgi Apparatus

b) Complete a table to describe what the following structures do in the cell and how their structure helps with their function(s). Use the description of the function of ribosomes as a guide.

c) Red blood cells (erythrocytes), ciliated epithelial cells and spermatozoa are three specialised cells. How does their structure aid them to carry out their functions?


Description of Organelle


Ribosomes function to read the code represented by messenger RNA, which is formed from the cell’s main DNA. Proteins are synthesised from this code meaning that the synthesis of all new proteins occurs from the ribosomes.


Chromatin is a formation of DNA and Proteins that result in Chromosomes. It functions is to switch DNA into reduced sizes suited to each cell. It is found in the nuclear membrane.

Endoplasmic reticulum

The Endoplasmic Reticulum (ER) has 2 types rough and smooth (RER and SER) that both have similar membranes and function as manufacturing and storage structures. However they are different shapes, the RER is called rough because it has ribosomes attached to it and the SER organelle has a storage function that is useful for releasing ions during activity when required.


Lysomes is found in eukaryotic cells; there function is to release enzymes to complete a digestion process in a cell. This function works to ensure that the cell is kept maintained from unwanted build up of molecules and particles.

Golgi Apparatus

Golgi Apparatus is a major organelle and is found in eukaryotic cells. It functions by appropriately packaging and processing protein molecules inside the cell to ensure that synthesisation is completed effectively prior to being sent out of the cell.


Flagella has a hair like structure and is found on cells that in theory move (swim), an example of a cell with flagella is Spermatozoa. The flagella supports the Spermatozoa (Male DNA) cell to travel through female reproductive system that completes conception.

Mitochondrion (Mitochondria)

Mitochondria function is to provide overall power or energy to the cell. They are primary identified to provide cellular respiration that enables the cell to complete the digestive process and preserve nutrients to retain energy for the cell.


The Nucleus is the intelligence of a cell that holds primary DNA. It controls the function and movement, eating and reproduction and is identified as a dark spot. That can be found siting in the fluid called cytoplasm (that is the liquid that fills a cell) in the middle of the cell.


Erythrocytes are Red Blood Cells (RBCs) and contain large amounts of Haemoglobin that are the molecules in red blood cells that carry oxygen from the lungs to other parts of the body. RBCs are also recognised for the movement of carbon dioxide from body tissues to the lungs.

Ciliated epithelial cells

Cilia epithelial cells are a hair like structure tissue that moves back and fourth that help move cells similar to the Flagella. An example of is Cilia epithelial tissue is found in female fallopian tubes. This tissue supports the movement of an Ovum (Egg) from the ovary into the uterus during monthly cycle.


Spermatozoa (Sperm) have a snake like structure that enables the head that holds the Male DNA and acrosome enzyme; the middle part holds mitochondria that provide energy to the cell and the tail that allows the part of the cell to move (swim) through the female reproductive system to enter the Ovum (Egg) that completes the conception process if successful.

(Word count: 400 words) + (Word count: 200 words) x600 = 519

TAQ 3: Discuss the statement above with reference to the composition of the cell membrane and the role it plays.

‘The cell membrane is a fluid mosaic model made up of lipids and protein molecules.’

The structure of lipid bilayer viewed through an electronic microscope is made up of 2 layers of lipid molecules. These lipids are referred to as phospholipids (fatty acids), these assemble in to bilayers that consist of a hydrophobic (non-water) region called the tail that avoids the water of the cell and hydrophilic (water- active) region referred to as the head that normally interacts with water of the cell forming the Head v Tail shape.

The lipid bilayer is the boundary that sets the internal and external environment of a cell within the plasma membrane. That protects and holds proteins, molecules and ions in to the cell, whilst ensuring communication across both environments is made.

WORD COUNT: 150 words 114

TAQ 4: Compile a table similar to the one below which compares and contrasts at least four features for the three transport processes for example use of energy and concentration gradient.

a) Define each one of these 3 processes.


Passive Transport (Diffusion)


Active transport

1. Use of energy

2. Movement

Scattering of particles

Movement of Gas (in Air or solution)

Water particles movement

Movement of water particles from a higher to lower concentration

Cell particles movement, energised through the membrane pump process. Cell energy that powers specific particles to be transported in and out of cells to form cellular respiration.

3. Concentration gradient

Passive Transport activity is more successful in larger concentrated areas as appose to a small area as space to support this process effectively.

Osmosis activity is more successful in transportation from a low diluted to a condensed (high concentrated) solution.

Active Transport activity works through high concentration of cells walls during the cell membrane pump process.

4. Function and Body

A higher temperature supports a quicker diffusion process to transport molecules around the body.

Water transportation by osmosis is essential to maintain water levels throughout the body.

Active transport process enables our cells to transport particles required throughout our body daily.

WORD COUNT: 300 words (total) for both sections 167

TAQ 5: Describe the structure and function of the four main types of tissues found in the human body. Complete a table similar to the one below.

Type of tissue

How the structure of the tissue is linked to function

Nerve tissue

Nerve tissue consists of neurons (nerve cells) that are sensitive and easily receptive to impulses, the structure is identified through the Brain, Spinal Cord and in the form of the peripheral nerves that enables impulses to be sent throughout the body.

Muscle tissue

Muscle tissue is identified in 3 types: Smooth muscle is found in the stomach, digestive tract, uterus, bladder and eye. It function is identified to control slow movement for example contraction during childbirth and pupil dilation movement.

Skeletal muscle covers the whole skeleton and controls all body movement including communication and facial expressions. Its additional function as a result of activity enables the body to produce heat that maintains body temperature.

Cardiac muscle is found only in the heart hence its name. This muscle type is unlike skeletal or smooth muscle tissue, as it does not get overused, It is identified to pump blood in to the heart and body by contraction and relaxation movement to form a pump process.

Connective tissue

Connective tissue consists of fibers, cells and intercellular substance this tissue type is predominantly found throughout the body that joins the body cell and muscle types together. Its primary function is to support all body parts effectively.

Epithelial tissue

Epithelial tissue, is the last of the 4 main tissue types of the human body, and consists of sheets of epithelia. It can be found in the interior and exterior of the body. Epithelial tissue function is diverse and is identified be determined by the number of cells layers and type it has been proven to be Protective, Sensory responsive, Excretion and Absorption.

WORD COUNT: 400 words (total) 282

TAQ 6: Breaking the whole of the body down in to systems, organs and tissues helps us analyse the workings of the body. By doing this we can understand the way in which things work individually and then fit together as a whole.

With the aid of diagrams for two organs of your choice:

a) List the types of tissue that make up each organ

b) Describe the function of each organ

c) Name two systems and explain the function of an organ within each system

d) Explain how the two organs interact to maintain the living processes of the body

A - B: The Digestive System(See Appendix 1)

The digestive system is where our food is broken down in to nutrients by organs that work together to ensure our body gets energy to develop and to restore itself. The four main tissues (Nerve, Muscle, Connective and Epithelial) can be found through the digestive system. Once food enters the stomach it is processed further to travel to the small intestine in order to enter the blood stream effectively, ensuring that any unwanted food is directed to leave the body.

C - D: The Urinary System (See Appendix 2)

The urinary system shares a connection with the digestive system and contains 2 key organs the Kidneys and Bladder. The Muscle, Connective and Epithelial tissues can be found throughout Urinary system, its function is to ensure that liquid waste is disposed from the body, in addition to regulating our blood pressure.

The overall process of the digestive system through to the urinary system is essential to maintain the body. Once all nutrients have been taking from the food and drink consumed there is waste produce called Urea. This is also filtered via the kidneys to be discarded through the urine process.

WORD COUNT: 250 words (total) 181

Bibliography: _________________________________________________________________________________

Appendix 1 The Digestive System

Appendix 2 The Urinary System __________________________________________________________________________________