Learning Objectives 1. Discuss facts about cells and the organisation - - PowerPoint PPT Presentation

Learning Objectives

• 1. Discuss facts about cells and the organisation of the

body

• 2. Outline the functions of the main cell components
• 3. Label a human cell

Starter – True or False

Name and explain the different types of tissue in the body

LO1: Discuss facts about cells and the organisation of the body

Decide if you think the following statements are TRUE or false.

1.

Groups of cells are known as tissues

2.

There are 5 different types of cells in the human body

3.

Cells are too small to be seen without magnification

4.

Tissues are grouped together to form an

• rgan

5.

Cells do not contain genetic material

5 minutes

• Every person is made up of billions of microscopic units called cells.

The cells carry out many chemical reactions and processes that allow us to live.

• Cells don’t usually exist in isolation, they are usually grouped

together with other similar cells carrying out particular tasks. Groups

• f cells are known as tissues
• Different types of tissues are commonly grouped together to form

an organ, which carries out a particular function.

• Groups of organs that are responsible for major tasks or functions in

the body are called body systems.

LO1: Discuss facts about cells and the organisation of the body

Organisation of the body

Make notes

Cells are too small to be seen without magnification. There are more bacterial cells in the body than human cells. Cells contain genetic material. The largest cell in the human body is the female ovum. There are about 200 different types of cells in the human body.

Interesting Cell Facts

LO1: Discuss facts about cells and the organisation of the body

https://www.youtube.com/watch?v=HBvfBB_oSTc&t=29s https://www.youtube.com/watch?v=URUJD5NEXC8 Watch the videos and make notes on the following:

• Cell Membrane
• Cytoplasm
• Nucleus
• Nucleolus
• Ribosomes
• Endoplasmic Reticulum (Rough &

Smooth)

• Golgi Apparatus
• Vacuole
• Lisosomes
• Mitochondria

LO2: Outline the functions of the main cell components

Task 1: Typical Human Cell

Research online to find further detail on each area of the human cell 20 minutes

• The cell membrane surrounds the cell and keeps all the components inside

the cell and prevents some materials out of the cell.

• The cell membrane allows some materials in and out of the cell and so it is

not a solid structure.

• The cell membrane is a phospholipid-protein bi-layer.
• Phospholipids are small, fatty molecules in two layers, with protein

molecules inserted at intervals through the bi-layer.

• Scientists use the fluid mosaic model to describe the organization of

phospholipids and proteins.

• The model shows you that phospholipid molecules are shaped with a head

and a tail region.

• The head section of the molecule likes water (hydrophilic) while the tail

does not (hydrophobic).

LO2: Outline the functions of the main cell components

Cell/Plasma Membrane

Check your notes & add any missing detail 5 minutes

• Because the tails want to avoid water, they tend to stick to each
• ther and let the heads face the watery (aqueous) areas inside and
• utside of the cell.
• The two surfaces of molecules create the lipid bilayer.
• Protein molecules often form channels through the membrane for

substances to pass to and from the cells. This structure is often termed the ‘fluid mosaic model’ of the cell membrane.

LO2: Outline the functions of the main cell components

Cell/Plasma Membrane

Check your notes & add any missing detail 2 minutes

• Cytoplasm is the semi-fluid that fills a cell.
• It is likened to a gel and capable of flowing slowly and keeps all the organelles

suspended in the cell.

• Many chemical reactions are carried out in the cytoplasm (metabolism).
• Complex stored sugars such as glycogen and melanin (the dark pigment

responsible for skin and hair colour) are found in cytoplasm.

• It uses its dissolved enzymes to break down all of those larger molecules. The

products can then be used by the organelles of the cell.

• Glucose may exist in the cytoplasm but the mitochondria can't use it for fuel.

The cytoplasm has enzymes that break glucose down into pyruvate molecules that are then sent to the mitochondria.

Cytoplasm

LO2: Outline the functions of the main cell component

Check your notes & add any missing detail 5 minutes

• The cell nucleus is a membrane bound structure that contains the cell's

hereditary information and controls the cell's growth and reproduction.

• Chromosomes are located within the nucleus. Chromosomes consists of

DNA, which contains hereditary information and instructions for cell growth, development, and reproduction. When a cell is "resting" i.e. not dividing, the chromosomes are organized into long entangled structures called chromatin.

• When a cell is dividing, the chromatin network separates into distinct

black threads known as chromosomes.

• There are 23 pairs of chromosomes in a human cell, containing specific

sequence of deoxyribonucleic acid (DNA), responsible for all our inherited characteristics such as hair colour and eye colour. These sequences of DNA are our genes.

LO2: Outline the functions of the main cell components

Nucleus

Check your notes & add any missing detail 5 minutes

• Every cell in the body has at least 1000 of these rod-shaped or spherical

bodies, and very energy active cells (like muscles and liver cells) will have many more.

• Mitochondria are concerned with energy release.
• Each has a double-layered membrane like the cell membrane

but the inner layer is folded at intervals, producing a series of ‘shelves’ or ridges known as cristae.

• The enzymes responsible for the end stages of glucose oxidation (for cell

reproduction) are located on the cristae.

• The energy released from glucose is trapped and stored until required by a

‘chemical battery’ called adenosine triphosphate (ATP).

• When energy is required for building complex molecules or doing work like

contracting muscles, ATP breaks down to adenosine diphosphate (ADP), releasing energy to build chemical bonds. ADP is then recycled. Check your notes & add any missing detail

LO2: Outline the functions of the main cell components

Mitochondria

5 minutes

❖ There are two variations, called rough and smooth ER. ‘Endo’

means within and ‘reticulum’ is a technical term for a network.

❖ ER is a branching network that fills the cell interior. ❖ The channels form passageways for transporting materials to and

from different parts of the cell.

❖ Rough ER is so called because it is studded with tiny

black bodies, known as ribosomes, and has the function of making cell proteins and acting as a temporary storage area. Some times sugars are added to the proteins to make glycoproteins, in secretions such as mucus.

❖ Smooth ER has no attached ribosomes and is

involved in the metabolism of lipids or fat.

LO2: Outline the functions of the main cell components

Endoplasmic Reticulum

5 minutes

• This appears as a series of flattened, fluid-filled sacs

stacked like pancakes. Many tiny fluid filled globules

• r bags lie close to stack and these are often known

as vesicles.

• The Golgi apparatus packages proteins for delivery

to other organelles and is responsible for producing lysosomes.

LO2: Outline the functions of the main cell components

Golgi Apparatus

2 minutes

• Lysosomes can be found in all parts of the cell cytoplasm and are small

vesicles.

• They contain powerful enzymes capable of digesting all major chemical

components of living cells, they are sometimes called ‘suicide bags’.

• Lysosomes can travel freely throughout the cell and, by releasing their

contents, they can destroy old or damaged organelles and even entire cells.

• Another of their functions is to destroy bacteria and other foreign materials,

such as carbon particles, that enter the cell. They do this by taking the foreign matter into their vesicles. After destroying the foreign matter with their enzymes, they release the digested material.

• Some types of white blood cells - phagocytes (eating cells), monocytes and

macrophages (large eaters) are loaded with lysosomes because their function is to destroy bacteria, viruses and foreign material entering the body cells and tissues.

• Many disease-causing agents are thought to be capable of damaging

lysosome membranes, bringing about internal cell destruction.

LO2: Outline the functions of the main cell components

Lysosomes

5 minutes

• Vacuoles are storage bubbles found in cells. They are found

in both animal and plant cells but are much larger in plant

• cells. Vacuoles might store food or any variety of nutrients

a cell might need to survive. They can even store waste products so the rest of the cell is protected from

• contamination. Eventually, those waste products would be

sent out of the cell.

• The structure of vacuoles is fairly simple. There is a

membrane that surrounds a mass of fluid. In that fluid are nutrients or waste products.

LO2: Outline the functions of the main cell components

Vacuole

2 minutes

• Cells need to make proteins. Enzymes

made of proteins are used to help speed up biological processes. Other proteins support cell functions and are found embedded in membranes. Proteins even make up most of your hair. When a cell needs to make proteins, it looks for ribosomes.

• Ribosomes are the protein builders or the

protein synthesizers of the cell. They are like construction guys who connect one amino acid at a time and build long chains.

LO2: Outline the functions of the main cell components

Ribosomes

4 minutes

Plenary

LO3: Label a human cell

From what you have learnt so far, can you correctly label the components of the cell?

• Nucleus
• Cell Membrane
• Lysosome
• Vacuole
• Ribosomes
• Rough

Endoplasmic Reticulum

• Smooth

Endoplasmic Reticulum

• Cytoplasm
• Golgi Apparatus
• Mitochondria