Eukaryotic Cell Structure

A level Biology Section - Cell Structure

What is the Ultra-structure?

The structure in the cell suited for its job.

What is the job of the Nucleus?

Contains organisms hereditary material and controls cell activities.

Nuclear Envelope

Double membrane, outer membrane is continuous with the RER, controls entry and exit of materials.

Nuclear Pores

Allows large molecules (RNA) out of the nucleus.

Nucleoplasm

Jelly, bulk of nucleus.

Nucleolus

Manufactures ribosomal RNA and assembles ribosomes.

Chromosomes

Protein bound, DNA.

What is the job of the Mitochondrion?

Site of aerobic respiration, make ATP (energy carrier molecule).

Double Membrane

Controls entry and exit of materials, inner membrane fold to form the cristae.

Cristae

Provide large surface area for attachment of enzymes for respiration.

Matrix

Contains protein, lipids and DNA.

What is the job of the Chloroplast?

Carry out photosynthesis.

Chloroplast Envelope

Double membrane, highly selective.

Grana

Stacks of thylakoids.

Thylakoids

Contains chlorophyll, where stage 1 takes place (light is absorbed).

Stroma

Fluid filled where stage 2 of respiration takes place (synthesis of sugars).

Granal Membrane

Large surface area for chlorophyll attachment.

DNA and Ribosomes

To quickly manufacture proteins.

What is the job of the Rough Endoplasmic reticulum?

Has ribosomes, provides large surface area for protein synthesis, provides pathway to transport materials.

Whats is the job of the Smooth Endoplasmic Reticulum (SER)?

Lacks ribosomes and is more tubular, synthesizes, stores and transports lipids/ carbohydrates.

What is the job of the Golgi Body/Apparatus?

Modifies proteins and lipids which are then transported in vesicles which move to the cell surface and fuse with the membrane to release contents.

Cisternae

Stacks of membranes (flattened sacs).

Vesicles

Small rounded hollow structures.

What is the job of Lysosomes?

Formed when vesicles contain enzymes, digest dead cells/worn out organelles, hydrolyses material ingested by WBC, release enzymes outside cell to destroy material around cell.

What is the job of Ribosomes?

Site of protein synthesis,consists of a large and small sub unit, contains ribosomal RNA and protein.

80s-Eukaryotic Cells

70s-Prokaryotic Cells, mitochondria and chloroplasts.

What is the job of the Cell Wall?

Strong (because of micro fibrils of cellulose) and contributes to cell strength, prevents cells from bursting by allows water to pass along it.

What is the job of the Vacuole?

Single membrane fluid filled sac (mineral salts, sugars, amino acids and wastes), supports herbaceous plants, temp food store, pigments attract pollinating insects.