This document outlines Keith Kiely's biology study from 2011-2013, covering topics such as the scientific method, cells, osmosis, enzymes and more. Each section provides definitions and explanations of key terms and concepts. The document appears to be notes taken by Keith Kiely to aid in his understanding of core biology topics.

1. Keith Kiely
Biology Study
Keith Kiely
2011-2013
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2. Keith Kiely
1. The Scientific Method
2. Life
3. Food
4. Cell Structure
5. Cell Diversity
6. Osmosis and Diffusion
7. Enzymes
8. Digestive System
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3. Keith Kiely
1. The Scientific Method
The scientific method is the way that the knowledge of the world is
found.
The main steps in the scientific method are:
 Observation
 Hypothesis
 Experiment
 Conclusion
 Relating conclusion to hypothesis
 Theory
Observation:
This is when you look at something in the world and then you question it.
Hypothesis:
It makes a guess about your observation. It is an explanation for an
observation.
Experiment:
This is carried out to see if your hypothesis is true or not. It is the basis of
the scientific method
Conclusion:
Is dependent on the result on the experiment that was carried out
Relation to Hypothesis:
Depending on the original hypothesis made before the experiment(s) the
result might support or reject it.
Theory:
After the hypothesis is proven right over a number of controlled
experiments, it becomes a theory.
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5. Keith Kiely
Scientific Limitations:
 Extent of knowledge
 Basis of investigation
 Ability to read results
 Changes in natural world
 Accidental discoveries
 Experiments
 Experiment design
 Safety
 Control experiments
 Sample size
 Random selection
 Replication
Extent of Knowledge:
If we knew more about something we can ask more questions
Basis of Investigation:
If there is a mistake in an investigation, the findings are not
valid
Ability to Read Results:
It can be difficult to read results and compare to original
hypothesis
Changes in Natural World:
The world is changing daily so findings must be revised
constantly
Accidental Discoveries:
Instead of following set rules for findings, they have been found
by accident
Experiments:
For an experiment to be carried out it must be agreed to follow
set rules
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6. Keith Kiely
Experiment Design:
Each experiment must be designed to look at one factor only so
one is being tested
Safety:
There is only so much things that can be done to keep the area
safe.
Control Experiments:
A controlled experiment can only have one aside from the
actual experiment
Sample Size:
If one simple animal or plant is being tested, the results may be
because of the living organism
Random Selection:
It is better to pick a sample to test completely at random so it’s
not biased selection
Replication:
You could post and publish your results so they can be known
and can be replicated.
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7. Keith Kiely
2. Life
What is life?
Life is processing all of these five things:
 Behaviour
 Response
 Excretion
 Nutrition
 Organisation
BRENO= Behaviour, Response, Excretion, Nutrition, Organism
Behaviour:
This is where living things and how they react in their surrounding
environment.
Their organs and cells help them react to Sound Smell Touch and Taste
Plants respond slower than animals and grow towards the light away from
their stimuli by photosyntsis.
Reproduction:
Is the production of a new individual or it is a group of new individuals.
Living things are produced by other living things called reproduction.
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8. Keith Kiely
Excretion:
Is the removal of waste from the body by chemical reactions
Nutrition:
This is the way that organisms get their food.
Plants can make their own food by photosyntsisand are called providers
Animals get their own food so they are consumers
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9. Keith Kiely
Organisation:
This just means that living this are organised by cells.
Cells turn into tissues, tissues to organs, organs to organ system, organ
system toindividual organs and individual organs to populations
Cells>>Tissue>>Organs>>Organ System>>Individual Organ>>Population
Metabolism:
This is all the chemical reactions in your body in one organism
Reactions Include:
 Digestion of food
 Speed of Repair
 Production of New Cells
 Production of Energy
 Rate of photosyntsis (plants only)
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10. Keith Kiely
3. Food
The Elements of Food:
There are 14 important chemical elements in food
The four main types are:
 Carbohydrates
 Lipids
 Proteins
 Vitamins
These are all called biomolecules
The six most common elements in food are:
 Carbon
 Hydrogen
 Oxygen
 Nitrogen
 Phosphorus
 Sulphur
The five main elements found dissolved in salt are
 Sodium
 Magnesium
 Chlorine
 Calcium
 Potassium
Carbohydrates:
The main elements in carbohydrates are
 Hydrogen
 Carbon
 Oxygen
The elements are presented as Cx(H2O)y
The elements X and Y are always going to be the same while H is
always double them
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11. Keith Kiely
Types of Carbohydrate:
There are three different types of carbohydrates:
 Monosaccharides
 Disaccharides
 Polysaccharides
Monosaccharides:
This is made up of one sugar molecule
Examples would be:
 Glucose
 Fructose
 Ribose
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12. Keith Kiely
Disaccharides:
This is made up of two monosaccharides.
Examples are
 Sucrose
 Lactose
Polysaccharides:
This is made up of many monosaccharide molecules.
Examples are:
 Starch
 Cellulose
 Glycogen
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Function of Carbohydrate
Structural function:
Cellulose forms Cell Wall
Metabolic Functions:
Glucose gives energy when we respire
Glycogen stores the energy in animals
Starch stores energy in plants
Protein
Protein always contains:
 Carbon
 Hydrogen
 Oxygen
All of these form to make amino acids.
Amino Acids are just building blocks of protein
Amino Acids>>Peptides>>Polypeptides>>Proteins
Sources of Proteins:
 Meat
 Fish
 Eggs
 Peas
 Beans
Functions of Proteins:
Structural Function:
Keratin is found in hair and skin and myosin found in the muscles.
Metabolic Functions:
Enzymes control the reactions and the antibodies fight infections.
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14. Keith Kiely
Lipids:
Lipids only contain the elements:
 Carbon
 Hydrogen
 Oxygen
Lipids include fat and oils
The basic unit for a lipid is triglyceride. Each one has one glycerol and
three fatty acids
Phospholipids are fatty substances that a phosphate group replaces fatty
acids
 Butter
 Cream
 Milk
 Meat
 Oils
 Fried foods
These are all rich in lipids
Functions of Lipids:
 Provides energy
 Stores energy
 Phospholipids form part of cell membrane
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15. Keith Kiely
4. Cell Structure
Animal Cell:
 Michcondrian
 Nucleus
 Cell Membrane
Plant Cell:
 Cell Wall
 Chloroplast
 Vacuole
 Nucleus
 Cell Membrane
Functions:
Animal:
Michcondrian:
Provides Energy
Nucleus:
Brain of Cell
Cell Membrane:
Let’s Components in and out of cell
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Plant:
Cell Wall:
Gives plant structure
Chloroplast:
Helps with photosyntsis
Vacuole:
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5. Cell Diversity
Tissues:
These are a group of cells working together for a similar function.
:
Plant tissues contain the following:
 Dermal Tissues
 Vascular Tissues
 Ground Tissues
Dermal Tissues:
This surrounds and it encloses the plants. Its location is in the leaf, the
stem and the roots. Its shape is rectangular with a tick strong wall with a
waterproof surface.
The function of the dermal tissue is to protect and to prevent water loss
Vascular Tissues:
This is for transportation; there are two types of vascular tissues.
These are:
 Xylem
 Phloem
Xylem:
This tissue does not contain nucleus and cytoplasm.
Tracheid’s and Vessels are two types of Xylem Tissues
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19. Keith Kiely
Mitosis
Mitosis is the process by which a cell duplicates its genetic information
(DNA), in order to generate two, identical, daughter cells. It is divided
into 4 stages, Prophase, Metaphase, Anaphase and Telophase. Most cells
divide by mitosis, these cells are called somatic cells and are generally
involved in growth. The other cells, germ cellsdivide by meiosis and are
involved in reproduction and gamete formation.
Mitosis divides genetic information during cell division.
Preperation
 The chromatin replicates itself
 The cell builds up a large store of energy
 Organelles either replicate or are made
Prophase
 First the chromatin condense to form chromosomes.
 They then double to form sister chromatids
 The membrane disappears and the centrioles separate and grow spindle
fibres
Metaphase
 The centrioles move to the poles and attach to the spindle fibres to the
centromere, which is the point where the sister chromatids are joined
together.
Anaphase
 The centromere splits
 The chromatids separate and are drawn to opposing poles
Telophase
 The centriole duplicates
 The nuclear membrane reforms
 The spindle breaksdown
 The cytoplasm divides in two
In plant cells a cell plate grows in the middle, and a cell wall is produced on
either side.
There are now two daughter cells, both of which are identicle to the original parent
cell.
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20. Keith Kiely
6. Osmosis and Diffusion
Diffusion:
Diffusion is the movement of the molecules from a region of high concentration to
a region of low water concentration.
It is a passive process; this means that it will not need an external force of energy
Examples of diffusion:
 Smell of Perfume
 Bread Making
 Stink Bombs
 Oxygen
Osmosis:
Osmosis is the movement of water molecules from a region of low concentration to a
region of high concentration.
Diffusion and Osmosis Compared:
 Both diffusion and osmosis involve in the moving of molicules from high to
low concentrations, this means it is passive.
 The difference between the two is that osmosis requires a semi-permuable
membrane and diffusion does not.
Semi-permeable Membranes:
Semi-permeable membranes let some molecules in and out of the cell and trap some
molecules into the cell.
Some of the molecules at can pass through it is:
 Water
 Oxygen
 Carbon dioxide
Some of the molecules that can’t easily pass are:
 Salt
 Sugars
 Proteins
Plant Cells in Concentrated Area:
 Cytoplasm has salt, starch, sugars and proteins dissolved in water
 If plant cell is left in distilled water in becomes less concentrated.
 Water passes through vacuole and becomes swelled, cell is a lot stronger.
 This is because of turgor pressure.
 This can be compared to air forced into a tyre
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21. Keith Kiely
Turgor pressure is the pressure of the vacuole and cytoplasm against the cell wall
Animal Cells in Concentrated Area
 If an animal cell like the red blood cells are placed in a dilute solution, water
will enter with osmosis
 The cells will expand and might burst because animal cells do not have a cell
wall
Osmosis and Food Preserving:
Placing food with bacteria or fungi in it in a very concentrated solution will make it
lose water by osmosis; this prevents the bacteria or fungi from growing and stops food
from decaying.
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22. Keith Kiely
7. Enzymes
Features of Enzymes:
An enzyme is a protein that spends up chemical reactions without being changed itself
Metabolism is the the sum of all chemical reactions taking place in an organism
Metabolism includes:
Reactions in which complex molecules are broken down. It is also known as
Catabolic Reactions.
Reactions on which complex molecules are formed. Also known as Anabolic
Reactions.
Energy Sources:
 The sun gives the original form of energy for all living things. In photosyntsis
the suns energy is converted into chemical energy in biomolecules such as
glucose
 Cellular energy from chemical bonds. This is released through respiration and
used by living things to allow metabolism
Features of Enzyme Action:
 The molecule that an enzyme reacts with is a substrate
 The molecules produced my an enzyme is the product
 Enzymes work because they have the correct shape to attach to the substrate
 Enzymes are specific. That means that the active site allows each enzyme to
join with one substrate
 Enzyme reactions are reversible. This means they can join molecules to form a
bigger one or break down to form smaller ones
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23. Keith Kiely
Factors Affecting Enzymes:
There are two Factors affecting enzyme action:
 Temperature
 pH
Temperature:
 At 0˚C water freezes to ice. This means that enzyme and substrate molecules
can’t move. Enzyme action is zero at this point.
 As temperatures increase, enzyme activity is faster. This causes them to
collide more often
 Human enzymes change their shape when it comes to 37˚C. above this
temperature reactions will fall
 As the temperatures get higher, enzymes become less useful and die. This is
called denatured
pH:
The pH scale runs in-between 0 to 14. 0 to 6 are acids, 7 are neutral and 8 to 14 are
basics.
 Most enzymes work best at a pH close to 7 (7-9)
 At higher or lower pH values the active site becomes altered
 Enzymes can be denatured by unsuitable pH levels
 Pepsin is an enzyme that is adapted to work in the stomach at a pH of 2
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24. Keith Kiely
Immobilised Enzymes:
Bioprocessing is the use is the use of enzyme controlled reactions to make a producer.
Immobilised enzymes are attached to each other or to an inert substance
Benefits:
 They are as efficient as isolated enzymes or sometimes more
 The product contains no enzyme so saves on separation costs
 The enzymes that are very expensive can be used over and over
Uses:
 Glucose is often used for sweeteners in drinks
 Penicillin is an antibiotic used to control bacterial growth
 Enzymes can be immobilised on paper or plastic and used to find certain
substances
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25. Keith Kiely
8. Human Nutrition and
Digestive System
Types of Nutrition:
Nutrition is the way which organisms gets and uses their food, the two types of
nutrition is:
 Autotrophic
 Heterotrophic
Autotrophic:
This type is when organisms can make their own foods. Examples would be, plants,
seaweeds and some bacteria
Heterotrophic:
This is when organisms get their food from the surrounding environment. Examples
would be, Animals, fungi, amoeba and some bacteria
There is three types of heterotrophic nutrition:
 Herbivores
 Carnivores
 Omnivores
Herbivores:
These are animals that feed only on plants. Examples would be, cattle, sheep and
rabbits.
Carnivores:
These are animals that feed on other animals. Examples would be, dogs and cats
Omnivores:
These are animals that feed on animals and plants. Examples would be, humans and
badgers
Events in Human Nutrition:
 Ingestion
 Digestion
 Absorption
 Egestion
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26. Keith Kiely
Ingestion:
Physical intake of food into the mouth
Digestion:
The physical and chemical breakdown of food. It is to allow small molecules of the
food to be absorbed in the small intestine
Absorption:
This happens when food passes through the small intestine and into the blood
Egestion:
This is when all the unabsorbed food passes through the anus
The Digestive System:
~~~~~~~~~~~~~~~~~~~~~~~~
The Mouth:
Physical Digestion is taken place in the mouth by the teeth. There is four types of
teeth, their names are:
 Incisors
 Canines
 Molars
 Pre-Molars
Incisors:
These are the four front teeth and used for cutting and slicing the food
Canines:
These are the two teeth, one either side of the Incisors and they are used for tearing
food
Molars/Pre-Molars:
These are all the back teeth and all are used for grinding and chewing the food
Chemical Digestion:
This is carried out in the mouth by the enzyme called amylase found in the saliva. The
pH in the mouth is between 7-8 which is the optimum pH for amylase to work on.
Amylase also digests starch to maltose
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27. Keith Kiely
9. Photosynthesis
Introduction:
Photosyntsis is the process of how plants make their own food. The sun gives light to
the plant and it combines with carbon dioxide and water to form glucose and oxygen.
Chlorophyll is used as catalysts in this process
The equation for Photosyntsis is:
6CO2 + 6H2O>>>chlorphyll+light>>>C6H12 + 6O2
Role:
Makes its own food
Makes food for animals (when eaten)
Forms oxygen for plants and animals
Formed fossil fuels
Location:
Sources of Light, CO2 and Water:
The Light Stage:
The Dark Stage:
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