Effectors I

Question 0

I. Vertebrate Muscle Types

Answer 0

A. Smooth Muscle - lines blood vessels, organs
- autonomic control
B. Cardiac Muscle - heart
C. Striated Muscle - skeletal muscle (e.g. limbs)
- under voluntary control (driven by motor neurons)

Question 1

Effectors I

Answer 1

I. Vertebrate Muscle Types
II. Skeletal Muscle
III. Sliding Filaments

Question 2

II. Skeletal Muscle

Answer 2

A. Tissue
 diagram
B. Muscle Fiber
 diagram
C. Myofibril
 diagram:
  contraction 1) z line closer together 2) I bands and H zones get  narrower 3) a bands remains same

Question 3

III. Sliding Filaments

parts

Answer 3

A. Filament Structure

B. Molecular Mechanism

Question 4

III. Sliding Filaments

A. Filament Structure

Answer 4

diagram: myosin filaments
Figure 39.2 Structure of skeletal muscle
Figure 39.3 Sliding Filament model of muscle contraction
diagram: myosin diagram:
contraction- produced by pulling actin PAST myosin; draws z lines closer

Question 5

III. Sliding Filaments

B. Molecular Mechanism

Answer 5

1. Energy: ATP -> ADP +Pi
2. Myosin uses energy to form CROSS-BRIDGES to actin and pull
   two diagrams
3. “Ratchet” Mechanism:

Question 6

III. Sliding Filaments
B. Molecular Mechanism
3. “Ratchet” mechanism

Answer 6

a) MYOSIN head binds to ATP
- > cleaves to ADP (still bound)
- > becomes ACTIVATED (“cocked”)

b) when actin is “EXPOSED” activated myosin binds & forms “cross bridges”

c) energy from ATP cleavage is released as:
1) myosin head springs back to original position, moving the BOUND actin &
2) releases ADP

d) myosin binds a new ATP & releases old cross bridge -> repeats cycle

Figure39.4 Myosin -Actin Interactions underlying muscle contraction
about 350 head groups per myosin filament
each head group makes about 5 cross-bridges during contraction

Question 7

about ___ head groups per myosin filament

Answer 7

350

Question 8

Each head group makes about ___ cross-bridges during contraction

Answer 8

5