Chapter 6 Cellular Organelles & Cell Strucuture

What is the role of each organelle in a eukaryotic cell?

How does compartmentalization support cellular function?

What is the structure and function of the nucleus?

Structure: nuclear envelope, double layered* membrane that surrounds nucleus;nuclear pores, protein line channels that control flow of molecules into and out nucleus;

Function: contains the cell’s DNA

How do nuclear pores regulate transport?

What is the structure and function of ribosomes?

• not organelles but grouped with them

• function: protein synthesis

• attached to rough ER

• lots of ribosomes in cells that need to create protein

What is the structure and function of the rough endoplasmic reticulum?

structure: ribosomes attached to rough ER

Function: protein folding and processing (chaperoning) accommodating to proteins (i.e. glycoproteins addition of sugars.

What is the structure and function of the smooth endoplasmic reticulum?

structure: no ribosomes on surface

function: creates lipids through lipid synthesis; detoxification of drugs; calcium storage

What are the cis and trans faces of the Golgi apparatus and their roles?

cis- receiving face (closest to rough er);proteins release from rough ER are dropped here

trans- distribution face (farthest from rough ER) proteins exit through trans face

proteins can go to:

1. secretes out of the cell

2. embedded in plasma membrane

3. Retained in the cytosol

Gigi apparatus = distribution center of cell

What is the function of transport vesicles?

transports proteins from roughy to Golgi apparatus; proteins released from Goji apparatus are release to transport bicycles

What is the function of lysosomes?

disposal

• anything that needs to be broken down is sent here

• Has digestive enzymes that breakdown, large molecules into smaller components

• acidic environment

What is the function of vacuoles, including the central vacuole?

• membrane bound pockets in cell

• large vesicles derived from ER and Gigi apparatus

• different types of vacuoles: food contractile, central, pigments hydrolytic

• Central vacuole: capturing waists and maintain acid balance of cell

What is the function of peroxisomes?

What is the function of mitochondria?

• sight of energy production

• cristae (folds) in inner membrane increases its surface

• has their own DNA inherited from mother

What is the function of chloroplasts?

What does the endosymbiotic theory explain?

mitochondria derives from prokaryotic cells

What evidence supports the endosymbiotic origin of mitochondria and chloroplasts?

1. organelles have double membranes

2. Organelles contained their own circular DNA

3. Organelles contain ribosomes that are like those of bacteria

4. Organized replicate independently of the cell

Why do mitochondria and chloroplasts have double membranes?

Why is circular DNA in mitochondria and chloroplasts significant?

What organelles are included in the endomembrane system?

Rough ER, transport vesicle, Golgi apparatus,

Describe the pathway of a secreted protein from synthesis to its final destination.

What role does the rough ER play in protein trafficking?

What role does the Golgi apparatus play in protein modification and sorting?

How are proteins directed to different destinations after Golgi processing?

Compare and contrast microfilaments, intermediate filaments, and microtubules.

microtubules

• the largest

• maintain cell shape, movement of organelles, and cell mobility

• important role in cell division

Microfilaments

• the smallest cytoskeletal protein

• important for muscle contraction

• main function to change shape

Intermediate filaments

• provide mechanical strength allow cell to maintain structure

What is the structure and function of microfilaments?

What is the structure and function of intermediate filaments?

What is the structure and function of microtubules?

How do microtubules function in cell division?

How do cytoskeletal components work together?

Compare and contrast prokaryotic, animal, and plant cells.

prokaryotic cells: no membrane, bound, nucleus or organelles; ribosomes present

What structures are unique to plant cells?

• Central vacuole - maintain balance inside cell; takes up 90% of cell volume; maintain ph of cell and pressure

• Chloroplast- site of photosynthesis, mainly found in plant cells

• Cell wall - to maintain shape; made of cellulose

What structures are unique to animal cells?

Where is DNA located in prokaryotic cells?

DNA in middle of the cell

What are plasmids?

Compare and contrast Gram-positive and Gram-negative bacterial cell walls.

What is peptidoglycan and what types of bonds form its structure?

Compare bacterial cell walls to plant cell walls.

What is the composition and function of the plant cell wall?