Year 1 Lesson 2: Travelling in and out of a cell - Osmosis - Diffusion

Osmosis supposes his toeses are roses.

Osmosis:-The description of osmosis is ' The movement of water across partially permeable cell membrane from a region of high water molecule concentration to a region of low water molecule concentration.

Things that need to get into a cell (travel via blood vessels):
Nutrients; minerals and vitamins, glucose, amino acids, lipids-fatty acids and glycerol, oxygen.

Things that need t oget out of a cell (via the veins):
C02, Urea

An animal cell is fully permeable to water. Don't get your cells wet, its bad for them, they explode.

Diffusion:- The movement of particles down a concentration gradient from high to low. Diffusion can be assisted by:

1.Increasing blood supply
2.Increasing surface area
3.Increasing concentration gradient
3 Increasing heat (not in biological systems though)

*Lungs have a very high surface area
Root cells and leaves have a very high surface area. Both are specialised.

I carried out two tests to demonstrate osmosis and diffusion. I will draw diagrams for them, but not today. They were very fun, one involved amonia, a boiling tube and litmus paper. The other one involved Visking tube (henceforth known as Viking tube), Starch, Glucose and Iodine.

Plant cells have cell WALLS this acts as a sort of armour. This means that the walls will prevent water freely passing into it and damaging it.

Year 1 Lesson 1: 09/09/2009: What is in Animal cells and Plant cells, Microscopy

An animal cell is made of several parts.

1.The cell membrane: Controls what goes in and out of a cell

2.Cytoplasm: Where it all happens, the chemical reactions take place here. The medium for the reactions of life

3.Mitochondria: Responsible for aerobic respiration

4. Ribosomes: Make proteins

5.Nucleus: Contains genetic material, DNA. Instructs how to make proteins

A plant cell is made of several different parts too

1.Cell wall: Keeps rigid shape

2.Cell membrane: Controls what goes in and out of the cell

3.Nucleus: Contains genetic material, instructions how to make proteins

4.Cytoplasm: Chemical reactions take place here

5.Chloroplasts: Photosynthesis occurs

6.Vacuole: Contains cell sap

7.Mitochondria

8.Ribosomes

(are ribosomes and mitochondria in plant cells?)

Misc

Cells (group together to form)> Tissues* (two or more combine for)> Organs (two or more combine for)>Organ system

*Four kinds

There are specialised cells. For example, red blood cells have no nucleus, are round and a large surface area

Sperm cells have a tail for getting about

White blood cells can change their shape to engulf microbes

Nerve cells can be very long and slender, and can carry nerve impulses over distances as long as one metre.

Using the microscope to look at cells from my cheek and onion cells

Getting a sample

1.Get a clean glass slide and a round glass wafer. Dry.

2.Get a swab and wipe it on the inside of cheek

3.Smear it on the glass slide

4.Drop blue dye over it, cover with round glass wafer.

Focusing the microscope

1.Plug in microscope

2. Carriage all the way up

3.Weakest lens, find the subject using coarse focus

4. Stronger lens, using fine focus

5. Stongest lens for detail

Put the microscope away obeying storage rules, flex around the upper to prevent melting, dust cover on, in cabinet.