Unit 3

Organelle

specialised structure in a cell. EG Golgi apparatus, mitochondria

Types of Cells

ProKaryotes, aswell as Eukaryotes

Prokaryotic Cells

Are unicellular and have a simple structure. Can be found everywhere, even in extreme environments. They lack a defined nucleus and membrane-bound organelles.

Eukaryotic Cells

Not only have a plasma membrane surrounding the cytoplasm bu has internal membranes that have specialised compartments.

Nucleic Acid

genetic material of all organisms, and they determine many of the features of an organism.

Protien

Organic compound and are present in every living organism and are essential to their structure and function

Enzymatic Protiens

Act as catalyst in biochemical pathways (enzymes)
SUch as amylase, that catalyse the breakdown of bonds

Hormonal Protiens

Coordinate an organism’s activites by triggering a response.
Insulin, glucagon

Immunological protiens

Protect against disease by recognising foreign bodies and microbes, also activate immune cells.

Immunoglobins (antibodies), complement, major histocompatibility complex proteins

Contractile and motor protiens

Contractile protiens aid muscle contraction

Motor protiens are responsible for the movement of cilia and flagella

structural protiens

provide support by forming the structural components of cells and organs

Assist in contractile functions in tissue such as muscle

Transport protiens

Transport of substances by acting as carrier molecules within or between cells

Recpetor protiens

Assist the cell in responding to a chemical stimuli

Storage protiens

Storage of metal ions and amino acids

Polypeptide chain

A chain of amino acids joined by peptide bonds is known as polypeptide chain

protien classifications

Fibrous protiens, are typically elongated and insoluble

Globular protiens are compactly folded and coiled into spherical tertiary and quaternary structures, generally insoluble.

Nitrogenous Bases

Adenine

Guanine

Cytosine

Thymine only in DNA

Uracil only in RNA

The structure of Genes

Promotor regions - binding region for the enzyme involved in the encoding process.

Exons - DNA regions that are the coding

Introns - DNA regions that are non coding segments

Anabolism

Build complex molecules from simpler subunits (for organic monomers, this involves condensation polymerisation)

catabolism

break down complex molecules into smaller components (for organic polymers, this involves hydrolysis reactions)

Biochemical pathways

Photosynthesis

Photo-respiration

Enzymes

Are globular proteins that act as biological catalysts and speed up reactions after binding to the substrate through the lock-and-key method.

Chloroplast

They are organelles in plant cells that convert light energy into chemical energy through photosynthesis

photosynthesis inputs and outputs