Plant and Animal Cell Structures and Organelles – QA Flashcards

A set of QA flashcards covering plant vs. animal cell differences and the structure and function of key organelles in the animal cell.

Which features are present in plant cells but typically absent in animal cells?

Plant cells have a cell wall and chloroplasts and lack centrioles (animal cells have centrioles).

Do plant cells contain centrioles?

No.

What are the two main components of the animal cell membrane that regulate interaction with the environment?

Pores that regulate ion flow and receptors that sense odors, tastes, and hormones.

How are the hydrophilic heads of the cell membrane oriented?

They face both the cell exterior and the aqueous cytosol.

What is the cytosol?

The watery fluid surrounding organelles; site of glycolysis and signal transduction; cytoplasm = cytosol plus suspended organelles.

What does the term cytoplasm refer to?

The cytosol plus the organelles suspended in it.

What is chromatin?

DNA packaged with proteins inside the nucleus; condenses into visible chromosomes during cell division.

Where is DNA contained in the cell during most of its life?

In chromatin within the nucleus.

What is the nucleolus and its function?

Located in the nucleus; ribosomes are made there and then move to the rough ER for protein synthesis.

What gives the rough endoplasmic reticulum its rough appearance?

Ribosomes on its cytosolic surface.

Where can ribosomes be found and what is their role?

Free in the cytosol and on the rough ER; they translate mRNA into proteins.

What are the main functions of the smooth endoplasmic reticulum?

Synthesis of lipids and steroid hormones; regulation of Ca++ release in muscle; detoxification of lipid-soluble toxins in the liver.

What is the Golgi apparatus and its function?

A stack of membrane-bound vesicles that packages and delivers enzymes and hormones; vesicles are sent to lysosomes, peroxisomes, and secretory vesicles.

What are lysosomes?

Vesicles filled with hydrolytic enzymes; release to cytosol can cause necrosis; immune cells deactivate bacteria by releasing contents to phagosomes.

What are peroxisomes?

Vesicles containing enzymes that break down hydrogen peroxide to water and oxygen; protect cells from oxidative stress.

What are secretory vesicles?

Vesicles formed in the Golgi that contain hormones or neurotransmitters and are SECRETED to the cell exterior.

What are animal cell vacuoles?

Small membrane-bound sacs involved in intracellular digestion and waste release.

What are the three main components of the cytoskeleton?

Microtubules, microfilaments, and intermediate filaments; they maintain cell shape, enable movement, move organelles, and assist in cell division.

What is the centrosome and what occurs during cell division?

Contains a pair of centrioles and organizes microtubules; centrioles replicate; the centrosome divides and the mitotic spindle forms to separate chromosomes.

What are centrioles?

Two perpendicular centrioles within the centrosome; each centriole is a ring of nine triplets of microtubules.

What are mitochondria and their primary function?

The cell’s powerhouses; produce ATP from sugar and oxygen via the inner membrane cristae.

What encloses the nucleus and how do molecules communicate with the cytosol?

A double membrane with nuclear pores allows exchange with the cytosol.

What happens to chromatin during cell division?

Chromatin condenses into visible chromosomes.

What determines cell characteristics and how is DNA conserved across cells?

Cell characteristics are determined by the active DNA; DNA is the same in all cells.

Where does glycolysis occur?

In the cytosol.