The Digestive System and Enzymes

You got this far without knowing what an enzyme is? Lies. But i'll cover it after this and then you will have to go back and read it all again to link up the enzyme to the properties. Forced double revision.

You need to know about quite a few places in the body though:

Mouth

• Food is moistened with saliva (comtains amylase enzyme that breaks down the starch)
• Food chewed to form bolus (ball-us... caus it's a ball of food... get it?)

Oespohagus

• Tube that takes food from mouth to stomach (peristalsis)

Liver

• Where bile is produced (neutralises stomach acid to allow enzymes to work)

Gall Bladder

• Where bile is stored (then released into small intestine)

Small Intestine

• Produces protease, amylase and lipase. (to break down food and aid digestion)
• Where energy from food is absorbed out into body

Stomach

• It pummels the food with its muscular walls (grrr... so manly)
• Produces protease enzyme (called pepsin)
• Produces hydrochloric acid
• To kill bacteria
• To give the right ph for the protease enzyme to work

Pancreas

• Protease amylase and lipase are produced here. (If only there was a SMALL INTESTINE link)

Large Intestine

• Where excess water is absorbed from the food.

Anus

• Hehehehehe.

Right! The Enzymes:

Digestive enzymes break down the big molecules into the smaller ones. Like a squishy thing... um... a compactor!

Eco friendly Rubbish. Literally.

 Except it breaks down... not compacts... well... scrap that. See, scrap that? Like scrap metal? *sigh*

So learn these:

• Carbohydrases: Break down (digest) starch into sugars.
• Proteases: digest proteins into amino acids.
• Lipase: digests fat to fatty acids and glycerol.

Cell Organisation and the Circulatory System

Let's not over complicate, you need to know the 3 definitions. And that's a whole topic covered.

"A TISSUE is a group of similiar cells that work together to carry out a particular function"

"An ORGAN is a group of different tissues that work together to perform a particular function."

"An ORGAN SYSTEM is a group of organs working together to perform a particular function."

 The Circulatory System
4 chambers, one heart. Sounds like a romantic and yet sadistic sex film. And then four major blood vessels, not so sexual.

This is the order it works in:

1. Right atrium recieves deoxygenated blood from the body (through the VENA CAVA)
2. De-oxygenated blood moves through to the right ventricle which pumps it to the lungs.
3. The left atrium recieves the oxygenated blood (through the PULMONARY VEIN)
4. The oxygenated blood then moved through to the left ventricle and is pumped around the whole body.  (via the AORTA)

Or to put it in a shorter and simpler way:

De-oxygentated - vena cava - body - right ventricle - lungs - oxygenated blood - left atrium - left ventricle- aorta - whole body

Please don't sue me CGP...

A few important things to remember would be:

• 4 chambers in the heart
• 4 major blood vessels
• Left ventricle has a thicker wall that right ventricle
• Why? It pumps blood around the whole body so more force is needed due to more distance needed to be covered.
• VALVES prevent the backflow of blood.

Growth And Development

How do you measure growth in an animal or a plant?

Hahahahahaha.... No. Do you know how much that joke has been overused? No, don't measure it with a ruler.

"Growth is an increase in Size or Mass"

Learn that, should make it much simpler.

Measure it in 3 ways:

1. Size (length and width... Go on, make a penis joke)
2. Wet Mass (Organisms have loads of water, so why not measure it with it in?)
3. Dry Mass (Oh... I take that back. You can take it out and weigh it aswell.)

Why do things grow?

• Cell differentitation (the cell becomes specialised. Like a cell university degree)
• Cell Division (Say hi to Mitosis again! That's miTosis... Not meiosis.)
• Cell elongation (where a PLANT cell expands. PLANT CELL. PLANT.)

Evidence for Evolution

This one will be short and sweet, just like a girl I know... Ah, how nice eh.

• FOSSILS
• Caused by gradual replacement by minerals, this is basically teeth and stuff being replaced by minerals and becoming rock like substances.
• Impressions left by the body in rocks such as clay.
• Preservation in extreme environments were enzymes can't work to decay them.
• Fossil record is created by all the physical characteristics left behind in fossils to create a sort of timeline of the different fossils.
• There are big gaps in the fossil record due to very few plants and animals actually becoming fossils, and soft tissue does not turn into fossils. Unhelpful if you ask me. And some fossils have not been found yet.

THE PENTADACTYL LIMB

A pentadactyl limbs is a limb with 5 digits. Does your hand have five digits? If only there was a theory of evolution that explained that...

Obviously it was dead when this was taken...

Distribution of Organisms And Enviromental Factors

If you can remember primary school you probably already know this topic. But if, like me, you have the memory of a goldfish, then you might need some revising.

First things first:

Why?

Why bother collecting organisms? So you know where they live! That's about it to be honest...

The face things:

1. Pooters

These are little beakers with tubes and a gauze. You suck into a tube and the other tube, preferably the one without the gauze on, sucks the insect up. The gauze on your side stops you being bugged... Get it? I'm sorry.

    2.  Pitfall traps

It's a pit... they fall into... See the diagram:

    3. Sweep nets

A net with a strong cloth that is used to collect insects and spiders and stuff from long grass.

    4. Pond Nets

Used for collecting things from... ponds...

Quadrats

Bit more to remember on these! Basically all you need to know is count the organisms you see in your quadrat then do it again with somewhere else so the same ones don't sneak in. Then learn this:

"MEAN = TOTAL NUMBER OF ORGANISMS/ NUMBER OF QUADRATS

Enviromental Factors

You can do these things to measure them, all you need to know:

1. Use a thermometer to measure the temperature in different places
2. Use a light sensor for light intensity
3. Measure soil PH using indicator liquid. Acid soil? What next! 

Osmosis And Plant Stuff

Osmosis

"Osmosis is the movement of water molecules across a partially permeable membrane from a region of high water concentration to a region of low water concentration."

Well... that was easy... So if there's lots of it in one place, it goes to where there is less! Like a pimp.

The Ladies be flocking.

Active Transport

The process of root hairs absorbing minerals from the soil. ODD thing to remember. Active transport uses energy from respiration to help pull minerals into the root hairs. Confusing heh? Well, this is because it is normally a lower concentration of minerals in the soil compared to the root hairs. So would diffusion work? Of course not! Along comes active transport with it's cheeky respiration energy.

Cheeky Bugger...

Transpiration

Final bit on this! Simple definition:

"Transpiration is the Loss of Water from the plant"

The water loses it through the water evaporating from the leaves. The leaves are adapted for this due to stomata. Looks like they've been doing their homework... If you're here I guess you haven't.

Look! Even 4 year olds' understand it.

Photosynthesis

"The way that plants cook their tea."

With jokes like that I should work for CGP! If there's a job going... i'll take it.

The simple one is at the bottom. The arrow is photosynthesis. You learn that? Topic covered.




Well... Nearly.  You need to know a few things about photosynthesis! The leaves are adapted for mor efficient photosynthesis and there are a couple of things that slow photosynthesis down:

• LIGHT
• CO2
• TEMPERATURE

Bright, hot and gassy. Bit like the sun... hm... if only there was a link between the sun and photosynthesis.