Eukaryotes PT 2

What is the primary function of mitochondria?

ATP production through cellular respiration.

Why are mitochondria thought to have evolved from bacteria?

They have circular DNA, 70S ribosomes, and divide independently.

What type of DNA do mitochondria contain?

Circular DNA.

What size ribosomes are found in mitochondria?

70S ribosomes.

How many membranes surround a mitochondrion?

Two.

What is the outer mitochondrial membrane derived from?

The host cell membrane.

What is the inner mitochondrial membrane derived from?

The ancestral bacterial membrane.

What are cristae?

Folds of the inner mitochondrial membrane.

Why are cristae important?

They increase surface area for ATP production.

Where does the electron transport chain occur?

On the inner mitochondrial membrane.

Where are chloroplasts found?

Plant cells and algae.

What is the primary function of chloroplasts?

Photosynthesis.

How many membranes surround chloroplasts?

Three.

What are thylakoids?

Flattened membrane sacs containing chlorophyll.

What are grana?

Stacks of thylakoids.

What is the stroma?

The fluid surrounding the thylakoids inside the chloroplast.

Where does photosynthesis occur?

In the chloroplast.

What pigment captures light energy?

Chlorophyll.

What is the main structure of the eukaryotic plasma membrane?

A phospholipid bilayer.

Which model describes the plasma membrane?

The Fluid Mosaic Model.

What molecule is found in animal cell membranes but not bacterial membranes?

Cholesterol.

What is the function of cholesterol in the plasma membrane?

Maintains membrane fluidity and stability.

What are sphingolipids involved in?

Cell signaling and membrane stability.

What are the three main membrane transport mechanisms?

Simple diffusion, facilitated diffusion, and active transport.

What is endocytosis?

The process of bringing materials into the cell.

What is phagocytosis?

The engulfment of large particles ("cell eating").

Which cells commonly perform phagocytosis?

White blood cells.

What is pinocytosis?

The uptake of fluids ("cell drinking").

What is receptor-mediated endocytosis?

Uptake of specific molecules after binding to receptors.

What is exocytosis?

The release of materials outside the cell.

Besides proteins, what else can exocytosis release?

Waste products.

Which eukaryotic organisms have cell walls?

Plants, fungi, algae, and some protists.

Do animal cells have cell walls?

No.

What is the primary component of plant cell walls?

Cellulose.

What is the primary component of fungal cell walls?

Chitin.

What is the function of the cell wall?

Support and protection.

What environmental stresses does the cell wall protect against?

Desiccation, osmotic pressure, and physical injury.

What is the extracellular matrix (ECM)?

A network of proteins and carbohydrates surrounding animal cells.

Which cells possess an extracellular matrix?

Animal cells.

What are the two major protein components of the extracellular matrix?

Collagen and proteoglycans.

What is the function of collagen?

Provides structural strength.

What is the function of the extracellular matrix?

Support, adhesion, and cell communication.

Where do many pathogens first attach in animal tissues?

The extracellular matrix.

What is the primary function of eukaryotic flagella?

Cell movement.

How are eukaryotic flagella different from bacterial flagella?

They whip instead of rotate.

What is the arrangement of microtubules in eukaryotic flagella?

9+2 arrangement.

How many pairs of microtubules surround the center?

Nine pairs.

How many microtubules are in the center?

Two.

Which motor protein powers eukaryotic flagella?

Dynein.

What causes eukaryotic flagella to bend?

Sliding of microtubules by dynein.

What is the primary function of cilia?

Move fluids or materials across the cell surface.

How are cilia different from flagella?

Cilia are shorter and more numerous.

What structure anchors both cilia and flagella?

The basal body.

What are basal bodies structurally similar to?

Centrioles.

What protein makes up microtubules?

Tubulin.

What organelle organizes microtubules during cell division?

The centrosome.

What is the mitotic spindle?

A structure that separates chromosomes during mitosis.

Which organelle is known as the powerhouse of the cell?

Mitochondrion.

Which organelle is known as the site of photosynthesis?

Chloroplast.

Which organelle modifies and packages proteins?

Golgi apparatus.

Which organelle detoxifies harmful substances?

Smooth endoplasmic reticulum and peroxisomes.

Which organelle digests worn-out cell parts?

Lysosome.

Which organelle synthesizes proteins for secretion?

Rough endoplasmic reticulum.

Which organelle stores genetic information?

Nucleus.