Biology Unit 1 & 2

Molecules

Two or more atoms chemically bond together to form molecules.

Organells

Molecules combined to form structures with specific cellular functions.

Cells

The building blocks of all living things.

Tissues

groups of similar specialised cells (and cell products) working together to carry out a particular function.

Organs

consists of two or more tissues that work together to complete a task.

Organ systems

two or more different organs that work together to perform a vital task.

Organism

Organ systems working together to contribute to the successful functioning.

Epithelial tissue

Tightly-packed cells that cover external and line internal surfaces.

Connective tissue

Loosely-packed cells that support, connect and store.

Muscular tissue

Elongated and contractile cells that allow movement.

Nervous tissue

Irregularly-shaped cells that sense stimuli and transmit signals.

Prokaryotic cells

do not contain a true nucleus, membrane bound organelles or linear DNA

Eukaryotic cells

do contain a true nucleus, membrane bound organelles and linear DNA

Cytoplasm

a jelly-like material, many chemical reactions occur here, houses a system of protein filaments that provides some internal support

Nucleus

contains the genetic material, plays a key role in directing many cell functions, the cell’s ‘control centre’

Nucleolus

located within the nucleus, ribosome production is controlled by this region

Ribosomes

the site of protein production

Cell (plasma) membrane

acts as a boundary between the internal and external environment, a selectively-permeable barrier  that controls what enters and leaves the cell

Cell wall

provides support, strength and protection, in plant, fungal, bacterial and some protist cells

Cilia and Flagella

enable movement in many unicellular organisms

Rough Endoplasmic Reticulum (ER)

acts as a transport system for substances

Golgi apparatus (Golgi body)

proteins are packaged into vesicles here

Lysosomes

increase the rate of digestion of ingested material inside the cell and will also break down the cell itself after it dies

Centrioles

direct chromosome movement during cell division

Vacuoles

storage sites of the cell

Mitochondria

process of aerobic cellular respiration occurs here

Chloroplasts

the major sites for photosynthesis

Scanning objective FoV

18mm (field number) / 4x (magnification) = 4.5mm = 4500µm

Low power objective FoV

18mm (field number) / 10x (magnification) = 1.8mm = 1800µm

High power objective FoV

18mm (field number) / 40x (magnification) = 0.45mm = 450µm

Real life size

diameter field of view (FoV) / number of cells that fit across FoV

Magnification

size of drawing / real life size

Phototaxis

when the whole of an organism moves towards or away from light.

Photosynthesis

the process of making complex ‘energy rich’ organic molecules (eg. sugars) from simple inorganic molecules (eg. carbon dioxide and water)

Photosynthesis equation

carbon dioxide  +   water ----> glucose  +  oxygen

Light dependent reaction

First stage of photosynthesis, in the grana, using chlorophyll pigments and water, and producing oxygen, hydrogen and ATP.

Light independent reaction

Second stage of photosynthesis, in the stroma, using carbon, oxygen and hydrogen, and producing triose phosphate, which forms glucose.

Disease

an abnormal condition of an organism which interrupts the normal bodily functions

Sign

an indicator of disease that can be detected (seen) or measured by another individual

Symptom

an indicator of disease experienced or felt by the individual affected by the disease

Non-infectious disease

diseases not caused by pathogens

Infectious disease

diseases caused by pathogens

Contagious disease

diseases that can be passed from one individual to another

Pathogens

a biological agent that can cause disease

Virulence

the ability of a pathogen to cause disease

Six types of pathogens

prions, viruses, bacteria, fungi, protozoa, multicellular parasites

Treatment

the use of an agent or procedure (such as a drug or surgery) in an attempt to cure or mitigate a disease condition

Transmission

the passing of a disease causing pathogen from an infected host individual to another individual or group

Vaccination

the use of a killed or weakened pathogen (or its antigens) to stimulate an immune response

Immunity

the ability of an organism to resist a pathogen (or its antigens) or a toxin

Prevention

inhibiting the introduction of a disease into an area, population or individual

Quarantine

the imposition of strict isolation to prevent disease spread

Epidemic

the occurrence of more cases of a disease than would be expected in a community or region during a given period

Pandemic

an epidemic of a disease that has spread across a large region

First line of defence

the use of physical and chemical barriers the use of physical and chemical barriers

Second line of defence

the use of the immune systems non-specific phagocytic white blood cells to kill antigens

Third line of defence

the use of the immune systems specific white blood cells to kill antigens

Cellular immunity

involves a special type of white blood cell called the T lymphocytes

Humoral immunity

involves a special type of white blood cell called the B lymphocytes

Antibodies

a specific protein made by B lymphocytes (or plasma cells)  in response to antigens

Antigens

molecules, usually found on the surface of pathogens, that promote a specific immune response

Herd immunity

a form of indirect protection from infectious disease that occurs when a large percentage of a population has become immune to an infection

Natural immunity

occurs when the immune response is not artificially induced

Artificial immunity

occurs when the immune response is artificially induced

Passive immunity

when pre-made antibodies are introduced into the body

Active immunity

when antibodies are actively made by a persons own B lymphocytes

Phospholipids

make up the ‘matrix’ of the cell membrane and are arranged in two layers to form a bilayer

Proteins

embedded in the phospholipid bilayer or are attached to the outer membrane surface, function as binding sites, receptor sites, transport facilitators, enzymes, antigens

Cholesterol

functions to increase flexibility of membranes at low temperatures

Carbohydrates

aid in cell recognition

Diffusion

the process where molecules move from an area of higher concentration to lower concentration until equilibrium is reached

Osmosis

a  process where water molecules move from areas of lower solute concentration to areas of higher solute concentration

Hypotonic

low concentration of solutes around the cell, water will enter the cell (net movement into the cell)

Hypertonic

high concentration of solutes around the cell, water will leave the cell (net movement out of the cell)

Isotonic

medium-level concentration of solutes around the cell (no net movement into or out of the cell)

Active transport

the movement of substances from areas of low concentration to high concentration

Bulk transport

the movement of ‘bulk’ material (relatively large volumes of substances)  into or out of the cell

Endocytosis

when substances enter cells via the cell membrane infolding and enclosing around particle

Exocytosis

when substances leave cells via a vesicle inside the cell fusing with the cell membrane and then the contents are expelled to the outside of the cell

Metabolism

the chemical activities that occur within cells

Inorganic molecules

do not contain carbon arranged in complex arrangements

Organic molecules

contain carbon arranged in complex arrangements

Macromolecules

biological molecules that are organic and large in size

Lipids

energy rich macromolecules that are water repelling and have an oily or greasy consistency, used as energy storage, insulation and make up the structure of cell membranes

Nucleic acid

macromolecules that are involved in inheritance and protein synthesis, vital to the operation and reproduction of cells

Enzymes

a biological catalyst that speeds up the rate of chemical reactions in organisms

Amylase

catalyse the breakdown of starch into maltose

Protease

catalyse the breakdown of proteins into polypeptide chain

Lipase

catalyse the breakdown lipids into fatty acids and glycerol subunits

Catabolic reaction

a chemical reaction in which large molecules are broken down into smaller ones

Anabolic reaction

a chemical reaction in which small molecules are built up into larger ones

Lock and key model

where the shape of the active site of enzyme (key) exactly fits the substrate (lock)

Induced fit model

where the shape of the active site of the enzyme changes slightly (active site moulds around substrate)

Cardiovascular system

the blood transport system that is also involved in regulating body temperature and osmotic balance

Cardiac cycle

complete heart beat

Systole

ventricular contraction

Diastole

ventricular relaxation

Blood pressure

a measure of the pressure in the blood as it travels through blood vessels around the body

Lymphatic system

a transport system that is involved in immunity and helps to transport fluid (lymph) away from body tissues

Aerobic cellular respiration equation

Glucose + Oxygen → Carbon dioxide + Water + Energy (ATP)

C₆H₁₂O₆ +6O₂ → 6CO₂ + 6H₂O + ATP