Cell Structure

Cognito flashcards

What is a cell?

The smallest unit of life that can live on its own. Cells make up all living organisms and their tissues.

What are the differences between eukaryotic and prokaryotic cells?

• Eukaryotic cells are much larger than prokaryotic cells.

• Eukaryotic cells contain membrane-bound organelles, while prokaryotic cells do not.

• Eukaryotic cells keep their DNA in the form of chromosomes within a nucleus, whilst prokaryotic cells have their DNA loose in the cell.

For animal, plant, and bacterial cells, state wether they are eukaryotic or prokaryotic.

• Animal and plants cells are eukaryotic.

• Bacterial cells are prokaryotic.

Name 5 organelles that are found in both animal and plant cells.

• Cell membrane

• Ribosomes

• Nucleus

• Mitochondria

• Cytoplasm

What is the cell membrane and what is its role?

It is a protective barrier around the outside of the cell. It controls which substances can pass in and out of the cell.

What is the cytoplasm and what is its role?

It is a jelly-like liquid that fills the cell. It allows substances to dissolve, and chemical reactions to take place.

What is the organelle labeled X?

Ribosome

What is the role of the nucleus?

It contains the genetic material (DNA) of the cell, therefore controlling what the cell does.

What is the role of the mitochondria?

They carry out aerobic respiration, therefore providing energy for the cell to use in chemical reactions.

What is the role of ribosomes?

They are the site of protein synthesis.

What is the organelle labeled X?

mitochondria

What is the organelle labeled X?

Cell membrane

Name 3 sub-cellular structures that are found in plant cells but not in animal cells.

• Chloroplasts

• Large vacuole

• Cell wall

In plants, what is the cell wall made of?

Cellulose

What is the organelle indicated in the photo?

A permanent vacuole

What is the role of the plant cell wall?

It provides strength and structure to the plant cell, preventing it from bursting or shrinking when water enters/leaves the cell via osmosis.

What does the permanent vacuole contain?

Cell sap

What is the role of the permanent vacuole?

It supports the cell, maintaining its turgidity (shape).

What is the role of chloroplasts?

Chloroplasts are the site of photosynthesis, so make glucose for the cell.

What sub-cellular structure is indicated by X?

Flagellum

What is chlorophyll?

A green pigment within chloroplasts that absorbs sunlight for photosynthesis.

Name 7 sub-cellular structures that are found in bacterial cells.

• Cell wall

• Cell membrane

• Cytoplasm

• Flagellum

• Ribosome

• Plasmid

• Circular strand of DNA (nucleoid)

What organelle is indicated by X?

Plasmid

What are plasmids, and what are their role?

Plasmids are small, circular loops of DNA that are separate to the main DNA. They contain extra genes that are sometimes useful to the bacteria, such as antibiotic resistance.

What is the prokaryotic cell wall composed of?

Peptidoglycan

What sub-cellular structures are indicated by A and B?

• A = Cell membrane

• b = Cell wall

What sub-cellular structure is indicated above?

Nucleoid (circular strand of DNA).