BIOC21H3 Lecture 6: BIOC21 Lecture 6 Notes

107 views7 pages

erincoyote93

28 Apr 2011

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Fairly straightforward unlike the others, there"s not a lot of subdivisions. Only have to worry about three types: smooth, skeletal, and cardiac. Smallest component: myofilament (protein structure within a muscle cell: actin or myosin) Tend to be organized into larger structures: myofibril (bundle of myofilaments) Myocyte: actual cell that contains the myofibrils composed of myofilaments. When we talk about muscle cells, we refer to them as fibres, which confuses most. Sarcosome: muscle cell; also referred to as the mitochondria of a cell (can be confusing, we won"t be using this term!) "pearls on a string" type of arrangement: actin filaments. We talk about actin and myosin, but there are more specific accessory proteins involved as well. When you want to initiate muscle contraction, you have to move tropomyosin out of the way. Actin is typically referred to as a thin filament; myosin referred to as a thick filament.

Related Questions

1) a) Describe the structure of vertebrate skeletal muscle using ALL the following words: myofilament, muscle fiber, sarcoplasmicreticulum, T tubules, myofibrils, nerves, blood vessels, connective tissue. Do not simply define these terms, but describe how they are arranged to form muscle.

b) In long bones such as the femur and humerus, where is spongy bone found in relation to compact bone?

c) Describe 3 ways vertebrate skeletal muscle differs from smooth muscle in terms of its structure (functions do not count).

silverbeaver496

broken down answers to help study

know which joint has no joint cavity
know the term for freely movablejoint
know the difference between syndesmoses,gomphosis, and suture and example for each.
know Synarthroses, Amphiarthroses andDiarthroses
know synchondrosis and examples forit
know different parts and components ofsynovial joints
know different types of movements likegliding, flexion, extension, circumduction and rotation.
know the structural category of synovialjoints and know examples for them
Know the different joint movements
know the functions of muscle
know isometric vs isotonic movment. Knowconcentric vs eccentric contraction
know different layers of connective tissuesurrounding a skeletal muscle
know the definition of fascicle,aponoresis, muscle fiber, myofibrils and myofilaments.
know how an action potential releases Cafrom SR
know different regions of a sarcomere,including A and I band, Z disc, H zone, M line etc
know the structures of thick and thinfilaments
know the sliding theory of musclecontraction
know the effect of Ach esterase
know the source of energy in skeletalmuscle, including glycolysis and its result
know the definition of a muscle twitch,unfused and fused tetanus
know different types of muscle fibers,slow oxidative, fast glycolytic and slow glycolytic fibers andtheir characteristics
know the difference between spasm andcramp
know oxygen debt, the reason and theresult
know different part of a curve for muscletwitch
know the process of smooth musclecontraction
know the role of caldesmon and calponin inmuscle contraction
know the counterpart of skeletal musclecomponents in the smooth muscle

rubysalmon267

1)Describe the directions in which the two motor proteins, kinesin and dynein, travel along a microtubule. Which of the two proteins moves materials towards the Golgi and which moves materials away from the Golgi? Lastly, what is the speed of kinesin dependent on?

2)What are microfilaments crucial for? How do they self-assemble? Which end do they prefer to elongate from?

3)Describe what types of filaments are in each of the bands of the sarcomere. As a muscle fiber is shortened, describe what happens to each of the bands in the sarcomere as the Z lines move inwards.

4)Describe the role of calcium ions in muscle contraction.

5)List the various types of actin-binding proteins

6) A. What are 3 functions of the cytoskeleton?

B.What are the three filaments that compose the cytoskeleton, and what are they composed?

7)How do they see the internal structures of cells in the microscope? What do proteins get labeled with?

8)Myosin II action (Figure 9.61) differs from that of kinesin (Figure 9.15) in that one of the kinesin heads is always in contact with a microtubule, whereas both myosin heads become completely detached from the actin filament. How are these differences correlated with the two types of motor activities in which these proteins engage?

9)If a myofibril were pulled so that the sarcomeres increased in length by approximately 50 percent, what effect would you expect this to have on the contractile ability of the myofibril? Why? What effects would this have on the H, A, and I bands?

10)Because cytoplasmic vesicles are seen to move in both directions within an axon, can you conclude that some microtubules are oriented with their plus end facing the axon terminus and others oriented with the opposite polarity? Why or why not?

BIOC21H3 Lecture 6: BIOC21 Lecture 6 Notes

Document Summary

Get access

Related Documents

BIOC21H3 Lecture Notes - Purkinje Fibers, Myocyte, Cardiac Muscle

BIOC21H3 Lecture : lect 5 --muscle

BIOC21H3 Lecture 5: Lecture 5-Muscle.docx

Related Questions