Saromeres

Question 1

Where are sarcomeres found?

Answer 1

Skeletal muscle cells, in myofibrils.

Question 2

What is the structure of a myofibril?

Answer 2

Repeating linear array of contracting sarcomeres

Question 3

What is the structure of a sarcomere?

Answer 3

Thin/thick fibrils. I bands at outer edges, A bands between those, H zone in center of A band. OTHER ZONES, review diagram

Question 4

How do skeletal muscles work?

Answer 4

Contracting

Question 5

What shortens when muscles contract?

Answer 5

Sarcomeres slide over each other

Question 6

What are thick filaments made of?

Answer 6

Several hundred myosin 2 molecules bound together with other proteins

Question 7

What happens during a contraction?

Answer 7

Myosin heads extend out and bind to thin filament, forming a cross bridge. Head undergoes conform. change, moving filament to center of sarcomere.

Question 8

How does myosin move so quickly?

Answer 8

Energy released by ATP hydrolysis induces a conformational change while the head is joined to the actin filament. which is amplified by swinging movement of alpha helical neck. Neck acts as a lever to swing whole molecule forward.