Unit 1 Biology As Revision notes

HideShow resource information
Preview of Unit 1 Biology As Revision notes

First 65 words of the document:

Biology and disease.
Rosie Darby
[Pick the date]
[Type the abstract of the document here. The abstract is typically a short summary of the contents of
the document. Type the abstract of the document here. The abstract is typically a short summary of
the contents of the document.]

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

A pathogen is a microorganism that causes disease. Pathogens include bacteria, fungi and viruses.
In order to become a pathogen the microorganism must:
Gain entry
Colonise the tissue of the host
Resist the defence system of the host
Cause damage to the host's tissues.
When a pathogen is transferred from individual to another it is known as transmission.
Common entry points of pathogens are:
Gas exchange system
Digestive system
These are known as interfaces, a surface or boundary linking two systems.…read more

Page 3

Preview of page 3

Here's a taster:

Physical activity
High blood pressure
Blood cholesterol levels
The general formula for monosaccharides is C(H2O)n
Disaccharides are formed from two monosaccharide's in a glycocidic bond. This is a condensation
Glucose + glucose = maltose
Fructose +glucose = sucrose
Glucose + Galactose = lactose
The Benedict 's test: tests for a reducing sugar by adding Benedict 's reagent and heating. If reducing
sugar is present will turn brick red.…read more

Page 4

Preview of page 4

Here's a taster:

A peptide bond joins one amino acid to another in a condensation reaction. It results in a dipeptide
and a water molecule.
Structure of proteins:
Primary ­ long repeating chain of amino acids joined by peptide bonds
Secondary ­ the hydrogen in the NH2 group has a positive charge joins with the oxygen with
has a negative charge to make hydrogen bonds. This produces an alpha helix or beta pleated
sheet.…read more

Page 5

Preview of page 5

Here's a taster:

The cell surface membrane is described as a fluid-mosaic model:
-fluid: as the phospholipid bilayer can move sideways freely within the plasma membrane
-mosaic: the pattern formed by the intrinsic and extrinsic proteins within the plasma membrane
Functions of the phospholipids in the membrane:
-allow lipid soluble substances to enter and leave the cell
-Prevent water soluble substances entering and leaving the cell
-provides flexibility
Magnification = size of image / size of object
Resolution power /resolving power is the minimum distance apart that…read more

Page 6

Preview of page 6

Here's a taster:

Digestion is done mechanically by the movement of teeth and muscle and chemically by hydrolysis.
Breakdown begins in the mouth where the salivary glands produce Amalyse. The saliva contains
buffers to prevent enzymes denaturing and erosion of teeth. Protein digestion begins in the stomach
and ends in the small intestine.
Once material rich blood goes through the small intestine it goes to the liver where it is detoxified.
Waste is stored in the rectum and then egested.…read more

Page 7

Preview of page 7

Here's a taster:

Enzyme Activity
Effects of temperature:
Increase in temperature means particles have more kinetic energy and so will move around
faster this means that there will be more enzyme-substrate collisions.
If the temperature is too high the enzyme denatures. This is because the bonds in the tertiary
and secondary structure are broken and so the enzymes active site is no longer specifically
shaped to a complementary substrate.…read more

Page 8

Preview of page 8

Here's a taster:

These are things that are required for the enzyme to work properly. They help the active site change
shape to allow the substrate to fit. They do not block the active site; instead they aid the shape and
can sometimes cause a ripple effect which is beneficial to its shape.…read more

Page 9

Preview of page 9

Here's a taster:

Important for protein synthesis
Prokaryotic and Eukaryotic cells
Prokaryotic Eukaryotic
DNA not in nucleus DNA enclosed in nucleus
Smaller 70S ribosomes Larger 80S ribosomes
No Golgi apparatus Golgi apparatus present
Uses food stores for energy Uses mitochondria to produce energy
No cytoskeleton Cytoskeleton
No double membrane bound organelles Double membrane bound organelles
Simple diffusion:
Movement of particles from an area of high concentration to an area of low concentration
Does not require energy/passive
Facilitated diffusion:
Protein provides a pore in the membrane or acts…read more

Page 10

Preview of page 10

Here's a taster:

Once it reaches the small intestine is uses flagella
It produces a toxin protein which consists of two parts, one binds to the carbohydrate
receptors and the other opens ion channels which cause CL ions to pass through to the lumen
The loss of chlorine raises the water potential in the cell and so water flows from the cells
into the lumen by osmosis
Oral rehydration
Cholera is treated by oral rehydration.…read more



really good :) 


these are amazing, thank you for uploading it! x


This notes are exactly what I've been looking for, thank you ! :)

Got another request tho :L, please do unit 2 as well if u can.

Cheers !! **

Similar Biology resources:

See all Biology resources »See all resources »