Prokaryotic vs Eukaryotic cells

Name the differences and similarities between prokaryotic and eukaryotic cells?

Differences:

• Pro has smaller 70s ribosomes Euk has larger 80s ribosomes

• Pro is smaller in size ~ 0.1-10 micrometers Euk is bigger in size ~ 10-100 micrometers

• Pro has no true nucleus, only a nucleoid region where DNA is found whilst Euk has a true nucleus where DNA's contained

• Pro DNA isn’t associated with histone proteins and has extra plasmids whilst Euk DNA is associated with histone proteins

• Pro cell wall made of murein, Plants= Cellulose, Fungi= Chitin, Animals= No cell wall

• Pro has no membrane-bounded organelles whilst Euk has membrane-bounded organelles

• Pro has a capsule for protection Euk doesn’t

• Pro DNA is circular whilst Euk DNA is linear

Similarities:

• Both have cytoplasm

• Both have cell membrane

Chloroplast

- Contains chlorophyll for absorption of light for photosynthesis (converts light energy to chemical energy- photo phosphorylation- produces ATP)

- Contains DNA and ribosomes so they can easily manufacture some of the proteins needed for photosynthesis

Mitochondria

- Site of aerobic respiration

- Produces ATP as a product of respiration (used by cells as an immediate source of energy)

- Therefore, cells with a high level of, of metabolic activity that require a lot of ATP (muscles cells have lots of large mitochondria)

Golgi apparatus

- A stack of membranes that form flattened sacs, called cisternae

- Collects, modifies and transports proteins (often adding non-protein components)

- Proteins, lipids and carbohydrates produced in the ER enter and are passed through the Golgi apparatus

- The proteins are then 'labelled' to be sent to their correct destination

- The modified proteins are transported in Golgi vesicles to their destination

Endoplasmic reticulum

- 3D system of me frames that spread throughout the cytoplasm of a cell

- Membranes form a network of tubules and flattened sacs called cisternae

- Its attached to the outer nuclear membrane

- 2 types of ER: Rough ER- synthesis and transport of protein, Smooth ER- synthesis and transport of lipids and carbohydrates

Lysosomes

- Form when vesicles that bud off the Golgi apparatus contain hydrologic enzymes (e.g lysozymes) for breaking down/ hydrolysing old/ unwanted material

- They hydrolyse material taken up by cells (phagocytic cells)

- Release enzymes to the outside of the cell in order to destroy external material

- Digest old, worn out, organelles for recycling

- Break down of cells that have died

Vacuole

- A fluid-filled sac with a single membrane

- Support herbaceous plants (not-woody/soft) or herbaceous parts of woody plants by making cells turgid/rigid

- Storage of useful substances for the plant cells

- Also storage of waste products (isolates materials that could be harmful to the cell)

Ribosomes

- Small granules found in all cells

- May either be found in the cytoplasm or be attached to the RER

- Have 2 subunits- a large and small

- Made of ribosomal RNA and protein

- 2 types: 80s (found in eukaryotic cells) larger, 70s (found in prokaryotic cells, mitochondria and chloroplasts) smaller

Cell wall

- Found in plant cells

- Made of cellulose fibres- very strong so supports the functions: providing the cell with strength to prevent it bursting due to osmosis, providing strength and support to the whole plant

- Fungi also have cell walls (chitin)

- Algae also have cell walls (cellulose or glycoproteins or both)

Nucleus

- Contains the organism's genetic material (in the form of DNA- chromosomes)

- Acts as the control centre of the cell- controls the cell's activities (through controlling protein synthesis)

- Nucleolus: where ribosomes are made

- Nuclear pores: allows small molecules and ions to freely pass, or diffuse, into or out of the cell

- Nuclear envelope: keeps cell's DNA separate from the rest of cell, protecting it from damage