Cell Biology: Function and Structure of Organelles

Questions and Answers

What is the structure of the nucleus?

Surrounded by the nuclear envelope

Contains a Nucleolus and Chromatin

Coils tightly into chromosomes during mitosis

All of the above (correct)

What is the function of the nucleolus?

The nucleolus is where ribosomes are made.

What is the function of the nuclear envelope?

Separates contents of the nucleus from the cell

Allows diffusion of substances

Contains pores for larger substances

All of the above (correct)

What is the main function of the nucleus?

It is the control center of the cell. Signup and view all the answers

What is the structure of the rough endoplasmic reticulum?

All of the above Signup and view all the answers

What is the function of the rough endoplasmic reticulum?

Acts as a transport system within the cell. Signup and view all the answers

What is the structure of the smooth endoplasmic reticulum?

A system of membranes with fluid-filled cavities Signup and view all the answers

What is the function of the smooth endoplasmic reticulum?

Contains enzymes that catalyze lipid metabolism. Signup and view all the answers

What is the structure of the Golgi apparatus?

A stack of membrane-bound flattened sacs. Signup and view all the answers

What is the function of the Golgi apparatus?

Modifies proteins and packages them into transport vesicles. Signup and view all the answers

What is the structure of mitochondria?

Surrounded by two membranes with a fluid-filled space between them. Signup and view all the answers

What is the function of mitochondria?

The site of ATP production during aerobic respiration. Signup and view all the answers

What is the structure of chloroplasts?

Large organelles surrounded by a double membrane. Signup and view all the answers

What is the function of chloroplasts?

The site of photosynthesis. Signup and view all the answers

What is the structure of a vacuole?

A fluid-filled sac surrounded by a tonoplast membrane. Signup and view all the answers

What is the function of a vacuole?

Filled with water and stores solutes. Signup and view all the answers

What is the structure of lysosomes?

Small bags with a single membrane containing powerful digestive enzymes. Signup and view all the answers

What is the function of lysosomes?

Keeps powerful digestive enzymes separate from the rest of the cell. Signup and view all the answers

What is the structure of cilia?

Short, hair-like outgrowths on the surface of a cell. Signup and view all the answers

What is the function of cilia?

They beat to facilitate movement. Signup and view all the answers

Study Notes

Nucleus

Surrounded by a nuclear envelope.
Contains the nucleolus and chromatin, which coils into chromosomes during mitosis.

Nucleolus

Site of ribosome production.

Nuclear Envelope

Separates nucleus contents from the cytoplasm.
Allows diffusion of substances; contains pores for mRNA and larger molecules.

Function of the Nucleus

Acts as the control center of the cell.
Stores the organism's genome and transmits genetic information.
Provides instructions for protein synthesis.

Rough Endoplasmic Reticulum (RER)

Consists of membranes with fluid-filled cisternae, continuous with the nuclear membrane.
Coated with ribosomes, facilitating protein synthesis.

Function of the Rough Endoplasmic Reticulum

Serves as a transport system within the cell.
Offers large surface area for ribosomes, aiding amino acid assembly into proteins.
Transports proteins to the Golgi apparatus.

Smooth Endoplasmic Reticulum (SER)

Composed of membranes with fluid-filled cisternae, continuous with nuclear membrane.
Lacks ribosomes on its surface.

Function of the Smooth Endoplasmic Reticulum

Contains enzymes for lipid metabolism, including cholesterol and steroid hormone synthesis.
Involved in lipid absorption and synthesis from the gut.

Golgi Apparatus

Made up of a stack of membrane-bound flattened sacs.

Function of the Golgi Apparatus

Modifies proteins by attaching sugars and lipids.
Folds proteins into their tertiary structures.
Packages proteins into vesicles for storage or secretion.

Mitochondria

Enclosed by two membranes; the inner membrane forms folds called cristae.
Contains a fluid-filled matrix, can vary in shape between spherical and rod-like.

Function of Mitochondria

Primary site for ATP production through aerobic respiration.
Self-replicating; abundant in energy-demanding cells like liver cells.

Chloroplasts

Large organelles found only in plant cells.
Surrounded by a double membrane; contains stacks of thylakoids with chlorophyll.
Each stack is called a granum, surrounded by fluid-filled stroma.

Function of Chloroplasts

Site of photosynthesis, where chlorophyll captures light energy to produce ATP.
Splits water to provide H+ ions, which reduce carbon dioxide into carbohydrates.
Abundant in leaf cells, particularly in the palisade mesophyll layer.

Vacuole

Fluid-filled sac surrounded by a tonoplast membrane, found in plant cells.

Function of Vacuole

Stores water and solutes, helping maintain turgidity and structure.

Lysosomes

Small membrane-bound bags containing powerful digestive enzymes.
Common in phagocytic white blood cells, aiding pathogen digestion.

Function of Lysosomes

Keep digestive enzymes separate from other cellular components.
Engulf and destroy old organelles or foreign matter.

Cilia

Short, hair-like structures on the cell surface containing microtubules and centrioles.

Function of Cilia

Beat in rhythmic patterns to facilitate movement or transport within the cell.

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Description

This quiz focuses on the functions and structures of key cellular organelles, such as the nucleus and nucleolus. Gain a deeper understanding of cellular components and their roles within the cell. Perfect for students studying cell biology or related subjects.