Summary list for 11.2 Movement
Skeletons and muscles
- Bones and exoskeletons (e.g. insect legs) provide anchorage for muscles and act as levers.
- Synovial joints allow certain movements but not others.
- Muscles work in antagonistic pairs.
Muscle contraction
- Skeletal muscle fibres are multi-nucleate and contain
- specialised endoplasmic reticulum.
- many myofibrils.
- made up of contractile sarcomeres.
- The sliding of actin and myosin filaments causes contraction.
- Contraction requires ATP hydrolysis and cross bridge formation
- Calcium ions and the proteins tropomyosin and troponin control muscle contractions.
Skills & applications
- Know how to annotate a diagram of the human elbow. Include cartilage, synovial fluid, joint capsule, named bones and named antagonistic muscles.
- The ability to draw labelled diagrams of the structure of a sarcomere, including Z lines, actin filaments, myosin filaments with heads, and the resultant light and dark bands.
- The ability to find the state of contraction of muscle fibres in electron micrographs,
- Experience of measurement of the length of sarcomeres using calibration of the eyepiece scale of the microscope.
Mindmaps
This diagram summaries the main sections of topic 11.2 about movement.
Test if you can draw something like these concept maps from memory.
Sarcomere structure
Understanding the structure of sarcomeres and their dark and light bands is an important skill from this topic.
Answer the question below on a piece of paper, then check your answer against the model answer below.
Grasshoppers jump using contraction of muscles in their legs. Explain the structure of myofibrils in muscles and the contraction of sarcomeres in the myofibrils. [8]
....................................................................................... ............................................................................
....................................................................................... ............................................................................
....................................................................................... ............................................................................
....................................................................................... ............................................................................
.
.
Click the + icon to see a model answer.
Multiple Choice questions
This is a self marking quiz containing questions covering the topic outlined above.
Try the questions to check your understanding.
START QUIZ!
List the roles of bones and exoskeletons in mammals and insects.
Bones and exoskeletons (e.g. insect legs) provide anchorage for muscles and act as levers.
The diagram shows the knee joint mammal
Which of the descriptions below correctly identifies the name of the structures X and Y and their function?
Synovial joints contain fliud which reduces friction and ligaments which allow certain movements but not others.
The diagram below shows the muscles and bones of the human arm and chest.
What is the term used to describe the arragement of muscles A and B?
Muscles work in antagonistic pairs by alternate muscle contraction and relaxation.
Skeletal muscle fibres are specialised cells.
Which of the following are adaptations of skeletal muscle fibres?
1. Specialised endoplasmic reticulum
2. Large central nucleus
3. Multi-nucleate cells
Skeletal muscle fibres are multinucleate and contain
- specialised endoplasmic reticulum
- many myofibrils
- made up of contractile sarcomeres.
The microscope images below shows some details of calibration of eyepiece and muscle tissue.
Estimate the length of a sarcomere in this image
In the left calibration image, 92 units corresponds to 65/100 of a mm
This is 650µm
The sliding of actin and myosin filaments causes contraction. Myosin filaments have 'heads' which form cross bridge connecting to actin causing it to move along the myosin filaments
The contraction of muscles requires activity from the sarcoplasmic reticulum.
Which of the following best describes the role of the sarcoplasmic reticulum?
Contraction of muscles requires cross bridge formation between actin and myosin filaments.
This forms after the calcium ions, released by the sarcoplasmic reticulum, bind with troponin and expose the myosin binding site
What happens inside a sarcomere when calcium ions bind to the protein troponin?
Calcium ions and the proteins tropomyosin and troponin control muscle contractions.
ATP hydrolysis is involved in the movement of the myosin head, which form the cross bridges.
The diagram below shows bones of the arm.
Which of the following correctly describes the labels P and Q?
Students should know how to annotate a diagram of the human elbow.
Include cartilage, synovial fluid, joint capsule, named bones and named antagonistic muscles.
The diagram below shows sarcomeres in the muscle of a rabbit
Which of the options below give the correct labels for the letter P, Q, R qnd S?
Students should have the ability to draw labelled diagrams of the structure of a sarcomere,
including Z lines, actin filaments, myosin filaments (with heads), and the resultant light and dark bands.
The elecron microscope image below shows part of a skeletal muscle.
How can you tell whether this muscle is contracted or relaxed?
The ability to find the state of contraction of muscle fibres in electron micrographs is required.
When the actin sides between the myosin there is a dark area of overlapping fibres. The more these overlap the more contracted the muscle is. In this case there is only a narrow area of overlapping fibres.
Everyone needs a bit of fun while they revise. Try this Movement topic card matching game.
Can you reach the leader board?
Twitter 
Facebook 
LinkedIn