lecture 2

Question 1

Microtubules

Answer 1

Long, slender, hollow tubes composed of tubulin molecules
* Maintain asymmetric cell shapes and coordinate complex cell movements
highways for transport of secretory vesicles within cell
* main structural and functional component of cilia and flagella
* position cytoplasmic organelles (ER, Golgi complex, lysosomes, and
mitochondria)
“bone and muscle” of the cell
* assemble into mitotic spindle

Question 2

Microfilaments

Answer 2

Smallest elements of the cytoskeleton
* Intertwined helical chains of actin molecules;
microfilaments composed of myosin molecules also
present in muscle cells
* Play a vital role in various cellular contractile systems,
including muscle contraction and amoeboid movement
(WBC or fibroblasts); serve as a mechanical stiffener for
microvilli

Question 3

Intermediate filaments

Answer 3

Intermediate filaments
* Irregular, threadlike proteins
* Help resist mechanical stress

Question 4

Intermediary Metabolism

Answer 4

• refers collectively to the large set of chemical reactions inside the cell that involve the degradation, synthesis,
  and transformation of small organic molecules such as simple sugars, amino acids, and fatty acids
  The intermediary metabolism occurs in the cytosol and involves thousands of enzymes.

Question 5

Substrate-level phosphorylation: The creatine phosphate system

Answer 5

CP is the first source of energy during muscle contractile activity!
* Stored in the cytoplasm
Enzymatic reaction catalyzed by the creatine kinase. This reaction is reversible
At rest in the skeletal muscle: 5X more CP than ATP. Most of the stored energy is in the form of
CP
* Skeletal muscle contraction: CP will replenish the used ATP. CP levels change faster than that
of ATP
* Only one enzymatic reaction: RAPID process (fraction of a second)

Question 6

how much atp produced total

Answer 6

32