Chapter 5.3.3 (Exam 1) Organelles

Question 1

In which cell types are vacuoles always present?

Answer 1

Plants and protists

Question 2

What is the function of vacuoles?

Answer 2

Provide structure for plant cells

Vacuoles also store anthocyanins in flowers and fruits; their color attracts pollinators

Question 3

How do vacuoles provide structure for plant cells?

Answer 3

Water enters vacuoles through osmosis, and the inflation of vacuoles creates turgor pressure

Question 4

What is the function of the cytoskeleton?

Answer 4

Supports and maintains cell shape

Holds organelles in position

Moves organelles

Involved in cytoplasmic streaming

Interacts with extracellular structures to hold cell in place

Question 5

What is the cytoskeleton composed of?

Answer 5

Composed of three types of filaments:

Microfilaments 7 nm

Intermediate filaments 8-12 nm

Microtubules 25 nm

Question 6

What is cytoplasmic streaming?

Answer 6

The continuous movement of the cytoplasm within a cell, which transports organelles, nutrients, and other cellular components throughout the cell

Question 7

Describe microfilaments.

Answer 7

Help a cell or parts of a cell to move

Determines and stabilizes cell shape

Made from the protein actin in long helical chains

Question 8

Describe intermediate filaments.

Answer 8

Tough, ropelike, protein structures that anchor cell structures in place

Helps resist tension

They are more permanent compared to the other two types of cytoskeleton

Question 9

Describe microtubules.

Answer 9

Long, hollow cylinders that act as a framework for motor proteins

Can change length rapidly by adding or losing tubulin dimers at plus or minus ends

Make up cilia and eukaryotic flagella