Cell structure and function

What is the structure and function of the ribosome?

Ribosomes are composed of ribosomal RNA (rRNA) and proteins; they serve as the site for protein synthesis.

How does the structure of the ribosome aid in its function?

The ribosome has two subunits that ensure the proper alignment of mRNA and tRNA for translating genetic information into proteins.

What are the three types of RNA involved in the ribosome?

Transfer RNA (tRNA), ribosomal RNA (rRNA), and messenger RNA (mRNA).

How does the ribosome demonstrate a common ancestry of all known life?

The structure and function of ribosomes are highly conserved across all species, indicating a shared evolutionary origin.

What is the structure and function of the rough ER?

The rough ER has ribosomes on its surface and is involved in the synthesis and processing of proteins.

How does the structure of the rough ER aid in its function?

Ribosomes attached to the rough ER allow for the direct translation of proteins into the ER for further processing.

What is the structure and function of the smooth ER?

The smooth ER lacks ribosomes and is involved in lipid synthesis, detoxification, and calcium ion storage.

How does the structure of the smooth ER aid in its function?

The tubular structure of the smooth ER provides a large surface area for the enzymatic processes involved in lipid synthesis and detoxification.

What is the relationship between the ribosome and the rough ER?

Ribosomes on the rough ER synthesize proteins that are either secreted from the cell or incorporated into membranes.

What is the structure and function of the Golgi?

The Golgi apparatus consists of stacked membrane-bound sacs, functioning to modify, sort, and package proteins for secretion.

How does the structure of the Golgi aid in its function?

Its flattened sacs provide distinct compartments for different stages of processing and modification of proteins.

What is the structure and function of the mitochondria?

Mitochondria are double-membrane organelles that produce ATP through cellular respiration.

How does the structure of the mitochondria aid in its function?

The inner membrane is folded into cristae to increase surface area for ATP production.

What is the structure and function of the lysosome?

Lysosomes are membrane-bound organelles containing digestive enzymes for breaking down waste materials.

How does the structure of the lysosome aid in its function?

The acidic interior of lysosomes and their membrane protects the rest of the cell from hydrolytic enzymes.

What is the structure of the vacuole?

Vacuoles are large, membrane-bound sacs that can store various substances.

What is the function of the food vacuole?

Food vacuoles are responsible for storing and digesting food particles.

What is the function of the central vacuole?

The central vacuole maintains turgor pressure and stores nutrients and waste products.

What is the function of the contractile vacuole?

Contractile vacuoles help regulate water balance by expelling excess water from the cell.

What is the structure and function of a chloroplast?

Chloroplasts contain chlorophyll and are involved in photosynthesis, transforming light energy into chemical energy.

How does the structure of the chloroplast aid in its function?

Thylakoid membranes within chloroplasts increase surface area for the light-dependent reactions.

What is passive transport?

The movement of substances across a cell membrane without the use of energy.

Identify two examples of passive transport.

Diffusion and osmosis.

What is active transport?

The movement of substances across a cell membrane using energy, typically against a concentration gradient.

Identify two examples of active transport.

Sodium-potassium pump and proton pump.

What is a concentration gradient?

The difference in the concentration of a substance across a distance.

What is endocytosis?

The process by which a cell engulfs material from the outside environment.

What is exocytosis?

The process by which a cell expels materials to the outside environment.

What does it mean if a solution is hypotonic?

A solution with a lower concentration of solutes compared to another solution.

What does it mean if a solution is hypertonic?

A solution with a higher concentration of solutes compared to another solution.

What does it mean if a solution is isotonic?

A solution with equal concentrations of solutes compared to another solution.

What is osmoregulation?

The process by which cells regulate their internal water and solute concentrations.

How does the membrane of organelles allow for specific processes to take place?

Membranes create distinct environments for specific biochemical reactions.

What is the endosymbiotic theory?

The theory that mitochondria and chloroplasts originated from engulfed prokaryotes that formed a symbiotic relationship.

Identify three differences between a prokaryotic and eukaryotic cell.

Prokaryotic cells lack a nucleus, are generally smaller, and do not contain membrane-bound organelles.

How is a prokaryotic cell compartmentalized?

Prokaryotic cells are not compartmentalized like eukaryotic cells; they lack membrane-bound organelles.