Biology Eukaryotic cell structure - 2.4

Biology 2.4 definitions beacuse it's easier to do it like this

Nucleus

Contains genetic information in the form of DNA. This controls the metaboic activity of the cell.

Nuclear envelope

Double membrane arond the nucleus to prevent damage

Nuclear pore

Allows molecules to move in and out of the nucleus (RNA)

Nucleolus

Area of nucleus responsible for producing ribosomes. Composed of proteins ofproteins and RNA

Mitochondria

Site of final stages of cellular respiration. Production of ATP molecule.

Cristae

highly folded membrane in mitochondria

Matrix

fluid interior in the cristae in the mitochondria

Mitochondrial DNA

DNA found in mitochondria

Vesicles

Membranous sacs consist of a single membrane with fluid inside. Vesicles are used to transport material in the cell.

Lysosomes

Specialised forms of vesicles thta contain hydrolitic enzymes. Responsible for breaking down waste maerial and organelles. Play an important role in the immune system

Cytoskeleton

Network of fibres necessary for shape and stability. Controls cell movement and movement of organelles. Present in cytoplasm of all eukaryotic cells

Microfilaments

Contractile fibres formed from actin. Cell movement and cell contraction during cytokenesis.

Microtubules

Globular tubulin proteins polymerise to form tubes. Scaffold structure determines cell shape. Tracks for movement of organelles,. Spindle fibres have a role in cell division.

Intermediate fibres

Give mechanical strength to the cell and help maintain integrity.

Centrioles

Component of the cytoskeleton composed of microtubules. Two centrioles form a centrosome in the assembly of spindle fibres.

Flagella

Whip like protrusions are used for cell motility, sensory organelle, detecting chemical changes in the environment

Cilia

Tail like protrusions that can be mobile or staitonary. Sensory organelles and movement of material. 9+2 microtubule structure.

Endoplasmic reticulum

Network of membranes enclosed around flattened discs called cisternae

Smooth ER

Lipid and carbohydrate synthesis and storage

Rough ER

Ribosomes bound to the surface. Protein synthesis and transport

Ribosome

Can be free floating in cytoplasm or on the rough ER. Made of RNA nd the site for protein synthesis.

Golgo apparatus

Plays a role in modifying proteins and packaging them into vesicles

Cisternae

The folded structue of the Golgi apparatus and the ER

Cis-face

Side of the Golgi apparatus facing the ER

Trans-face

Side of the Golgi apparatus facing away from the ER

Cytoplasm

Made of water and cytosol. The site of chemical reactions

Cell-surface membrane

semi-permeable membrane responsible for controlling organelles entering and leaving the cell.