Lesson 5: The heart

We learned about the heart during the first half of the lesson. During the second half we took a test to see if we are on track and able to continue. I hope I did well, but I have sinced realised that I crossed out a correct answer and replaced it with an incorrect one. That's worse than being straight out wrong. :-(
When I have access to a scanner, I shall put some of my diagrams on the board. I may be able to tell what they are meant to represent. I may not.


The heart

• Pumps blood thru the body
• Blood flows from the heart to the organs thru arteries and returns thru veins
• In the organs, blood flows thru capilaries (veins and arteries are too think to allow anything thru)
• Substances needed by cells in the body tissues pass out of the blood, and substances pruduced by the cells pass into the blood thru the walls of the capillaries

There are two separate circulation systems, one to the lungs and one to all the other organs of the body. Lungs are the start and end of the circulation, the heart is the booster in the circuit.


Out of the heart = Arteries
Into the hear = Veins


Blood plasma transports

• Carbon dioxide from the organs to the lungs
• soluble products of digestion from the small intestine to other organs

Blood
Red blood cells transport oxygen from the lungs to the organs.
Red blood cells have no nucleus, they are packed with a red pigment called Haemoglobin.
In the lungs, haemoglobin combines with oxygen to form Oxyhaemoglobin
In other organs it splits into haemoglobin and oxygen


Present in blood are:

• Red blood cells
• White blood cells
• Plasma
• Platelets

Plasma contains
Nutrients
hormones
water
carbon dioxide
urea


Red blood cells carry haemo globin, which combines with oxygen in the lungs to form oxyhaemoglobin. Cells of all the organs want this.

Week 4: Enzymes

Enzymes are proteins, composed of amino acids. They speed up chemical reactions in cells, but remain unchanged. A catalyst.

Two types of chemical reactions that may occur:

Anabolic - Building up: Protein Synthesis, Photosynthesis
Catabolic - Breaking down: Respiration

Enzyme processes inside cells are called Intracellular. Enzyme processes outside of cells are called extracellular.


Enzymes have an optimum temperature at which they work, beyond which they function less well, or break completely. Enzymes that have been heated up too much are said te be 'de-natured' and they cannot be used again.


Here are some locations in the body and the enzymes that work there.

Mouth: Amylase

Stomach: Protease

Pancreas: Amylase, Protease, Lipase

Small intestine: Amylase, Protease, lipase


Here is what those particular enzymes do

Amylase > Starch to sugars

Protease > Proteins to amino acids

Lipase > fats to glycerol


Catalase is the fastest known enzyme. It converts hydrogen peroxide to water and oxygen.



Test, Fast Froth.

1. Cut two pieces of liver (from a lamb) to the same size
2. Put 1 into a boiling tube containing 5cm3 of hydrogen peroxide
3. Use a ruler to measure the highest point of the resulting froth and the time it took to reach that point.
4. Do the same with the second piece of liver, but this time cut it into small pieces

Which test causes froth to rise the quickest, highest? Why?
Where is the enzyme found in this test? Was the enzyme a breaker or a builder, a catabolic or an anabolic?


Recap with bullets

Enzymes

• Are proteins
• Made of Amino Acids
• Biological Catalyst - Speeds up reaction, remains unchanged
• Will be damaged at too high a temperature, or the wrong ph - De-natured
• Can be used again and again
• Human enzymes tend to work best at 37 degrees
• Fulfill one specific role - reaction or process
• Anabolic process builds
• Catabolic process breaks down

Enzymes in metabolism

• Intracellular -eg photosynthesis
• Extracellular - eg digestion
• anabolic - Protein synthesis, photosynthesis
• Catabolic - respiration

So, Photosynthesis is an intracellular anabolic enzyme process.

Week 3: Nutrition

Food, yum. Tasty and useful for it is made of:

Proteins, Carbohydrates, Fats, Vitamins, Minerals and Water. Food= Energy Energy is measured in Joules or Calories.

Energy is needed for:

Activities
Growth
Repair

Chemical reactions+Metabolism=Metabolic rate - Migh metabolic rate= High rate of reactions

Too much unused energy can lead to Obesity, which can lead to Heart Disease, High Blood pressure, Diabetes, Arthritis.

Too little energy can lead to Malnourishment - Deficiency diseases, reduced resistence to infection and irregular periods.

Nutrients in foods if not in balance can cause harm.
Too much saturated fat
Increases cholesterol, can lead to heart and blood vessel disease.
High Density Lipids is good cholesterol (will reduce plaque formation) Low Density Lipids is bad cholesterol (leads to the formation of plaques). THe balance of LDL-HDL is important and determined by diet and inherited factors. Eating poly and monounsaturated fats can reduce cholesterol.

Too much salt
Can lead to an increase of blood pressure in 30% of population. Processed foods tend to be high in salt and fat.

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.