BIO MODULE 2:Set 4 — Mitochondria & Cytoskeleton

What is the main function of mitochondria?

Cellular respiration and ATP production.

Why are mitochondria called the powerhouse of the cell?

They capture energy from food molecules and produce ATP.

What is cellular respiration?

The breakdown of energy-rich food molecules to capture energy in ATP, producing carbon dioxide and water.

What gas do mitochondria require for the aerobic cellular respiration described in the lecture?

Oxygen.

How many membranes surround a mitochondrion?

Two membranes.

What is the mitochondrial matrix?

The inner compartment enclosed by the inner mitochondrial membrane.

What are cristae?

Folds of the inner mitochondrial membrane where ATP-generating reactions occur.

Do mitochondria contain their own DNA?

Yes, they contain DNA and machinery for some of their own protein synthesis.

What are the three major components of the cytoskeleton?

Microtubules, intermediate filaments, and microfilaments.

Which cytoskeletal component is the thickest?

Microtubules.

Which cytoskeletal component is the thinnest?

Microfilaments.

What proteins make up microtubules?

Tubulin proteins.

How many protein filaments form the wall of a microtubule?

13.

What does microtubule polarity mean?

Microtubules have distinct positive and negative ends.

At which end do microtubules usually add or lose tubulin dimers more rapidly?

The positive (+) end.

What are the main functions of microtubules?

Maintaining cell shape, moving organelles, moving chromosomes during cell division, and supporting cilia and flagella.

What is a centrosome?

A region near the cell centre from which microtubules radiate.

What are centrioles?

Barrel-shaped structures made of nine triplets of microtubules arranged in a ring.

What is the difference between cilia and flagella?

Cilia are generally shorter and more numerous; flagella are longer and usually fewer.

What is the 9+2 arrangement?

Nine outer microtubule doublets surrounding two central microtubules in eukaryotic cilia and flagella.

What motor protein drives the bending of eukaryotic cilia and flagella?

Dynein.

What are intermediate filaments?

Cytoskeletal fibres that provide structural support to cells and tissues.

What are microfilaments made of?

Two intertwined strands of actin.

What motor protein works with actin in muscle movement and other cellular processes?

Myosin.

What is cytoplasmic streaming?

The flow of cytoplasm that helps distribute nutrients, proteins, and organelles within a cell.