CH.4 - Cell Organelles

U2 - The Cell (Hailee Oppmann)

What is the structure that surrounds the nucleus?

The nuclear envelope.

What is the function of the nucleolus?

Produces mRNA and assembles ribosomal subunits.

What is chromatin?

A complex of DNA and proteins that organizes DNA replication and regulates gene expression.

What is the difference between cytoplasm and cytosol?

Cytoplasm includes all contents within the cell membrane excluding the nucleus, while cytosol is the liquid portion of the cytoplasm.

What are ribosomes and where are they found?

Ribosomes are particles made of RNA and proteins that translate mRNA into polypeptides, found freely in cytosol or attached to the rough endoplasmic reticulum.

What is the rough endoplasmic reticulum (RER)?

A network of membranes studded with ribosomes that folds, modifies, and packages proteins for transport.

What is the function of the smooth endoplasmic reticulum (SER)?

Synthesizes lipids, detoxifies drugs and poisons, stores calcium ions, and metabolizes carbohydrates.

What is the role of the Golgi apparatus?

Modifies, sorts, and packages proteins and lipids for delivery to various destinations in the cell.

What is the structure and function of lysosomes?

Lysosomes are membrane-bound vesicles that contain hydrolytic enzymes for digesting macromolecules, old organelles, and pathogens.

What is Tay-Sachs disease related to?

It is caused by the absence of an enzyme in lysosomes that digests a fatty substance, leading to neurological problems.

What is the structure of mitochondria?

Mitochondria have a double membrane with a smooth outer membrane and an inner membrane folded into cristae, containing its own DNA and ribosomes.

What is the primary function of mitochondria?

Produces ATP through cellular respiration.

What is the structure and function of chloroplasts?

Chloroplasts are double-membrane organelles found in plant cells that contain thylakoid membranes and are the site of photosynthesis.

What are peroxisomes and their function?

Peroxisomes are small membrane-bound sacs that contain oxidative enzymes to break down fatty acids and detoxify alcohol.

What is the function of vacuoles in cells?

Vacuoles store water, ions, pigments, toxins, and maintain turgor pressure in plant cells.

What limits cell size?

The surface to volume ratio; as cell size increases, volume increases faster than surface area.

What is the function of ribosomes attached to the endoplasmic reticulum?

They produce proteins for secretion, membranes, or lysosomes.

What is autophagy?

The process by which lysosomes destroy nonfunctional organelles and portions of cytoplasm.

What is the structure of the endoplasmic reticulum?

A membranous system of channels and saccules that is continuous with the nuclear envelope.

What do lysosomes assist with in white blood cells?

They help digest pathogens that are engulfed by the cells.

What is the role of signal peptides in protein synthesis?

They bind to receptors on the rough endoplasmic reticulum to initiate protein synthesis.

What is the significance of the inner membrane of mitochondria being folded?

The folding increases the surface area for ATP production during cellular respiration.