Copy of 10.02.20 (Sync + Async) - Sliding Filament Model (5/28/2026)

Last updated about 3 hours ago

22 questions

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Copy of 10.02.20 (Sync + Async) - Sliding Filament Model (5/28/2026)

Last updated about 3 hours ago

22 questions

Sliding Filament Model

Objectives: Students will...
differentiate between the proteins, enzymes, and other biochemicals important in the Sliding Filament Model of muscle contraction
differentiate between the steps involved in the Sliding Filament Model of muscle contraction
write a love letter or story about various proteins involved in muscle contraction

1

Part 1: Skeletal Muscle Structure
The Sliding Filament Model is our current understanding of how the skeletal muscles of the body contract.  While there are some differences between skeletal muscle and cardiac muscle contraction, cardiac muscle contraction is similar.  

1

Draggable item		Corresponding Item

1

Now let's talk about thick and thin filament in a little more detail.  Examine the picture of thick and thin filaments below while answering questions 6-9.

1

Draggable item		Corresponding Item

1

Compare and contrast troponin and tropomyosin.

1

What questions do you still have about Part 1: Skeletal Muscle Structure?

Part 2: The Neuromuscular Junction
Skeletal muscle only contracts when it is activated by the nervous system.  Nervous system cells, like muscle cells, are excitable - this means that they can send messages within their cells using electrical signal.  If not for the electrical signals of your nervous and muscle cells, we would not exist as we do today.

Communication between the nervous cells and muscle cells requires another form of communication: chemical communication.  Neurotransmitters are the chemicals used to relay messages from a nervous cell to a muscle cell.  While we will learn more about neurotransmitters when we get to the nervous system next semester, a basic understanding of this signaling is important in understanding how muscles contract.

1

Draggable item		Corresponding Item

1

Compare and contrast the roles of Na+ and Ca2+ in muscle contraction.

1

What questions do you still have about Part 2: The Neuromuscular Junction?

Part 3: The Art of Muscle Contraction
Ok- you know the structures.  Now let's focus on HOW they work together to contract skeletal muscles.

1

Draggable item		Corresponding Item

1

Describe the relationship between tropomyosin, troponin, myosin, and actin

1

What questions do you still have about Part 3: The Art of Muscle Contraction

Part 4: Putting it All Together
Think about parts 1, 2, and 3 as you answer questions 16-20.

1

What is still confusing about the Sliding Filament Model?

1

Refer back to Section 10.2 or Section 10.3 of your textbook and fill in your confusion.

How did the textbook help? What are you still confused about?

Before you move on, go back to #19 and try to re-sequence the steps.  You can use your notes this time!

Then, re-watch the Crash Course:

Do you need to resequence again?  What things make sense now that didn't make sense before?

7

Role: Some type of protein involved in muscle contraction (Acton, Myosin, Tropomyosin, Troponin)
Format: Love Letter
Topic: Your feelings towards another protein (or proteins) involved in muscle contraction. You should discuss / refer to the following in your letter:
actin
myosin
tropomyosin
troponin
ATP
ADP and P
water
Ca2+
thick filaments
thin filaments
sarcomeres
myofibril
Z-lines
mitochondria

Sliding Filament Model

Objectives: Students will...
differentiate between the proteins, enzymes, and other biochemicals important in the Sliding Filament Model of muscle contraction
differentiate between the steps involved in the Sliding Filament Model of muscle contraction
write a love letter or story about various proteins involved in muscle contraction

Put the following muscle structures in order from largest to smallest.

Fascicle
Myofibril
Muscle fiber (muscle cell)
Muscle

Categorize the following substances as proteins or ions.

Na+
Myosin
Actin
Ca2+
Titin
Tropomyosin
Troponin

Protein
Ion

Part 1: Skeletal Muscle Structure
The Sliding Filament Model is our current understanding of how the skeletal muscles of the body contract.  While there are some differences between skeletal muscle and cardiac muscle contraction, cardiac muscle contraction is similar.  

First, identify the following as true or false:

Myofibrils are smaller than sarcomeres.

Then, draw a picture justifying your answer.

True

False

The picture below displays a simplified version of a single sarcomere.

Match the terms with the correct letter on the diagram.

Draggable item		Corresponding Item
G		A band
C		Z line
A		H zone
H		Sarcomere
D		Thin filaments
B		Thick filaments
E		I band
F		Myosin heads

Which of the following best describes the difference between the A band and the I band?

The A band is the same length as the thin filament.  The A band does not change in length during muscle contraction.
The I band is the distance between the Z-lines of a sarcomere.  The I band gets shorter during muscle contraction.

The A band is the same length as the thick filament.  The A band does not change in length during muscle contraction.  
The I band is the distance between the end of one thick filament and the beginning of another thick filament in a neighboring sarcomere.  The I band gets shorter during muscle contraction.

The A band is the same length as the thin filament.  The A is the same length as the thin filament.
The I band is the distance between the Z-lines of a sarcomere.  The I band does not change in length during muscle contraction

The A band is the same length as the thick filament.  The A band gets shorter during muscle contraction
The I band is the distance between the end of one thick filament and the beginning of another thick filament in a neighboring sarcomere.  The I band does not change in length during muscle contraction.

Now let's talk about thick and thin filament in a little more detail.  Examine the picture of thick and thin filaments below while answering questions 6-9.

Match the following proteins with the structure they are on

Troponin
Myosin
Actin
Tropomyosin

Thick filaments
Thin filaments

Which of the following best describes thick filaments?

They have a "hinge" region, which is flexible (like a hinge on a door) and myosin heads.

The myosin heads contain binding sites where they attach to troponin

The myosin heads contain binding sites where they attach to actin.

Thick filaments have ATP, ADP, and P binding sites.

Thick filaments are made of a protein called myosin.    

Thick filaments are made of a protein called tropomyosin.

What binds at each of these sites on myosin?

Draggable item		Corresponding Item
B		Actin
A		ATP

Compare and contrast troponin and tropomyosin.

What questions do you still have about Part 1: Skeletal Muscle Structure?

Part 2: The Neuromuscular Junction
Skeletal muscle only contracts when it is activated by the nervous system.  Nervous system cells, like muscle cells, are excitable - this means that they can send messages within their cells using electrical signal.  If not for the electrical signals of your nervous and muscle cells, we would not exist as we do today.

Communication between the nervous cells and muscle cells requires another form of communication: chemical communication.  Neurotransmitters are the chemicals used to relay messages from a nervous cell to a muscle cell.  While we will learn more about neurotransmitters when we get to the nervous system next semester, a basic understanding of this signaling is important in understanding how muscles contract.

Watch the following video about the neuromuscular junction. Remember that we have not yet talked about the nervous system and that we will learn more about neuron structure and action potentials next semester. For now, focus on the terms provided below.

Draggable item		Corresponding Item
Acetylcholine (ACh)		Space between neuron and muscle cell
ACh Receptors		Neurotransmitter released from neuron
Ca2+		Proteins on the membrane of the muscle cell that bind to ACh
Synaptic cleft		Ions that enter the muscle cell when enough ACh has attached to the muscle cell receptros
Na+		Ions that enter the neuron and trigger the release of ACh

Compare and contrast the roles of Na+ and Ca2+ in muscle contraction.

What questions do you still have about Part 2: The Neuromuscular Junction?

Part 3: The Art of Muscle Contraction
Ok- you know the structures.  Now let's focus on HOW they work together to contract skeletal muscles.

Watch the following video on muscle contraction.
(Note: You may watch the whole thing, but the beginning is review. He'll start talking about skeletal muscle contraction at 1:45)

As you watch, match the terms below with the best description.

Draggable item		Corresponding Item
Tropomyosin		Protein
Titin		Long, "strink-like" protein blocking the binding sites on actin
Troponin		Binds to the protein troponin in order to expose myosin binding site on actin
Myosin		Small protein attached to tropomyosin when muscle is at rest; binds to Ca2+ during muscle contraction
Ca2+		Protein holding the thick filaments in place

Describe the relationship between tropomyosin, troponin, myosin, and actin

Ok - Let's talk more about ATP. Examine the picture below, focusing on Adenosine Triphosphate (ATP), Adenosine Diphosphate (ADP), and Phosphate (P).

Which of the following statements about the role of ATP, P, and ADP in muscle contraction are accurate?

ADP and P detach from the myosin head when the myosin head attaches to actin

ATP turns into ADP and P when the myosin head moves back to its "ready" position

ATP attaches to the myosin head when the myosin head detaches from actin binding sites.

ATP turns into ADP and P when the myosin head pulls the thin filaments 'in'

ATP detaches from the myosin head when the myosin head detaches from actin binding sites.

ATP --> ADP + P

ADP + P --> ATP

ADP and P attach to the myosin head when the myosin head attaches to actin

Think back to this simplified description of ATP hydrolysis that we saw the other day (left) and compare it to the more complex, accurate description on the right.

Which of the following best describes ATP hydrolysis?

ATP --> ADP + P Reaction is exothermic: more energy is released than used up

There is a net gain of energy when ATP --> ADP + P

ATP --> ADP + P Reaction is endothermic: more energy is used up than is released

ATP releases water when it forms ADP and Phsophate

There is a net loss of energy when ATP --> ADP + P 

ATP reacts with water to form ADP and Phosphate.  

What questions do you still have about Part 3: The Art of Muscle Contraction

Part 4: Putting it All Together
Think about parts 1, 2, and 3 as you answer questions 16-20.

WITHOUT LOOKING AT YOUR NOTES: Put the following steps of muscle contraction in the correct order. The order should go from before a contraction --> contraction

Acetylcholine crosses the synaptic cleft and binds to receptors on the muscle fiber
Calcium ons (Ca2+) bind to troponin molecules
ATP binds to myosin, disconnecting the crossbridge
Myosin heads rotate towards the center of the sarcomere, bringing the Z-lines closer together
Calcium ions (Ca2+) are released from the sarcoplasmic reticulum of the muscle cell
ATP reacts with water, forming ADP and phosphate. The energy created is used to move the myosin head back to its original position.
The shape of troponin is altered, causing tropomyosin to move and expose the actin binding sites on the thin filaments
The myosin heads of the thick filaments attach to the actin binding sites on the thin filaments, forming a cross bridge
Sodium ions (Na+) enter the plasma membrane of the muscle cell. Potassium ions (K+) exit the plasma membrane of the muscle cell
ADP and phosphate are released fom their binding sites on the myosin heads

What is still confusing about the Sliding Filament Model?

Refer back to Section 10.2 or Section 10.3 of your textbook and fill in your confusion.

How did the textbook help? What are you still confused about?

Before you move on, go back to #19 and try to re-sequence the steps.  You can use your notes this time!

Then, re-watch the Crash Course:

Do you need to resequence again?  What things make sense now that didn't make sense before?

Role: Some type of protein involved in muscle contraction (Acton, Myosin, Tropomyosin, Troponin)
Format: Love Letter
Topic: Your feelings towards another protein (or proteins) involved in muscle contraction. You should discuss / refer to the following in your letter:
actin
myosin
tropomyosin
troponin
ATP
ADP and P
water
Ca2+
thick filaments
thin filaments
sarcomeres
myofibril
Z-lines
mitochondria

Put the following muscle structures in order from largest to smallest.  

Fascicle

Myofibril

Muscle fiber (muscle cell)

Muscle

Categorize the following substances as proteins or ions.

Na+

Myosin

Actin

Ca2+

Titin

Tropomyosin

Troponin

Protein

Ion

First, identify the following as true or false: 

Myofibrils are smaller than sarcomeres.

Then, draw a picture justifying your answer.

True

False

The picture below displays a simplified version of a single sarcomere.  

Match the terms with the correct letter on the diagram.

G

A band

C

Z line

A

H zone

H

Sarcomere

D

Thin filaments

B

Thick filaments

E

I band

F

Myosin heads

Which of the following  best describes the difference between the A band and the I band?

The A band is the same length as the thin filament.  The A band does not change in length during muscle contraction.
The I band is the distance between the Z-lines of a sarcomere.  The I band gets shorter during muscle contraction.

The A band is the same length as the thick filament.  The A band does not change in length during muscle contraction.  
The I band is the distance between the end of one thick filament and the beginning of another thick filament in a neighboring sarcomere.  The I band gets shorter during muscle contraction.

The A band is the same length as the thin filament.  The A is the same length as the thin filament.
The I band is the distance between the Z-lines of a sarcomere.  The I band does not change in length during muscle contraction

The A band is the same length as the thick filament.  The A band gets shorter during muscle contraction
The I band is the distance between the end of one thick filament and the beginning of another thick filament in a neighboring sarcomere.  The I band does not change in length during muscle contraction.

Match the following proteins with the structure they are on

Troponin

Myosin

Actin

Tropomyosin

Thick filaments

Thin filaments

Which of the following best describes thick filaments?

They have a "hinge" region, which is flexible (like a hinge on a door) and myosin heads.

The myosin heads contain binding sites where they attach to troponin

The myosin heads contain binding sites where they attach to actin.

Thick filaments have ATP, ADP, and P binding sites.

Thick filaments are made of a protein called myosin.    

Thick filaments are made of a protein called tropomyosin.

What binds at each of these sites on myosin?

B

Actin

A

ATP

Watch the following video about the neuromuscular junction.  Remember that we have not yet talked about the nervous system and that we will learn more about neuron structure and action potentials next semester.  For now, focus on the terms provided below.

Acetylcholine (ACh)

Space between neuron and muscle cell

ACh Receptors

Neurotransmitter released from neuron

Ca2+

Proteins on the membrane of the muscle cell that bind to ACh

Synaptic cleft

Ions that enter the muscle cell when enough ACh has attached to the muscle cell receptros

Na+

Ions that enter the neuron and trigger the release of ACh

Watch the following video on muscle contraction.  
(Note: You may watch the whole thing, but the beginning is review.  He'll start talking about skeletal muscle contraction at 1:45)

As you watch, match the terms below with the best description.

Tropomyosin

Protein

Titin

Long, "strink-like" protein blocking the binding sites on actin

Troponin

Binds to the protein troponin in order to expose myosin binding site on actin

Myosin

Small protein attached to tropomyosin when muscle is at rest; binds to Ca2+ during muscle contraction

Ca2+

Protein holding the thick filaments in place

Ok - Let's talk more about ATP.  Examine the picture below, focusing on Adenosine Triphosphate (ATP), Adenosine Diphosphate (ADP), and Phosphate (P).

Which of the following statements about the role of ATP, P, and ADP in muscle contraction are accurate?

ADP and P detach from the myosin head when the myosin head attaches to actin

ATP turns into ADP and P when the myosin head moves back to its "ready" position

ATP attaches to the myosin head when the myosin head detaches from actin binding sites.

ATP turns into ADP and P when the myosin head pulls the thin filaments 'in'

ATP detaches from the myosin head when the myosin head detaches from actin binding sites.

ATP --> ADP + P

ADP + P --> ATP

ADP and P attach to the myosin head when the myosin head attaches to actin

Think back to this simplified description of ATP hydrolysis that we saw the other day (left) and compare it to the more complex, accurate description on the right. 

Which of the following best describes ATP hydrolysis?

ATP --> ADP + P Reaction is exothermic: more energy is released than used up

There is a net gain of energy when ATP --> ADP + P

ATP --> ADP + P Reaction is endothermic: more energy is used up than is released

ATP releases water when it forms ADP and Phsophate

There is a net loss of energy when ATP --> ADP + P 

ATP reacts with water to form ADP and Phosphate.  

WITHOUT LOOKING AT YOUR NOTES: Put the following steps of muscle contraction in the correct order.  The order should go from before a contraction --> contraction

Acetylcholine crosses the synaptic cleft and binds to receptors on the muscle fiber

Calcium ons (Ca2+) bind to troponin molecules

ATP binds to myosin, disconnecting the crossbridge

Myosin heads rotate towards the center of the sarcomere, bringing the Z-lines closer together

Calcium ions (Ca2+) are released from the sarcoplasmic reticulum of the muscle cell

ATP reacts with water, forming ADP and phosphate.  The energy created is used to move the myosin head back to its original position.

The shape of troponin is altered, causing tropomyosin to move and expose the actin binding sites on the thin filaments

The myosin heads of the thick filaments attach to the actin binding sites on the thin filaments, forming a cross bridge

Sodium ions (Na+) enter the plasma membrane of the muscle cell.  Potassium ions (K+) exit the plasma membrane of the muscle cell

ADP and phosphate are released fom their binding sites on the myosin heads

Copy of 10.02.20 (Sync + Async) - Sliding Filament Model (5/28/2026)

Copy of 10.02.20 (Sync + Async) - Sliding Filament Model (5/28/2026)

Sliding Filament Model

Part 1: Skeletal Muscle Structure

Compare and contrast troponin and tropomyosin.

What questions do you still have about Part 1: Skeletal Muscle Structure?

Part 2: The Neuromuscular Junction

Compare and contrast the roles of Na+ and Ca2+ in muscle contraction.

What questions do you still have about Part 2: The Neuromuscular Junction?

Part 3: The Art of Muscle Contraction

Describe the relationship between tropomyosin, troponin, myosin, and actin

What questions do you still have about Part 3: The Art of Muscle Contraction

Part 4: Putting it All Together

What is still confusing about the Sliding Filament Model?

Refer back to Section 10.2 or Section 10.3 of your textbook and fill in your confusion. How did the textbook help? What are you still confused about?

Sliding Filament Model

Put the following muscle structures in order from largest to smallest.

Categorize the following substances as proteins or ions.

Part 1: Skeletal Muscle Structure

First, identify the following as true or false: Myofibrils are smaller than sarcomeres.Then, draw a picture justifying your answer.

The picture below displays a simplified version of a single sarcomere. Match the terms with the correct letter on the diagram.

Which of the following best describes the difference between the A band and the I band?

Match the following proteins with the structure they are on

Which of the following best describes thick filaments?

What binds at each of these sites on myosin?

Compare and contrast troponin and tropomyosin.

What questions do you still have about Part 1: Skeletal Muscle Structure?

Part 2: The Neuromuscular Junction

Watch the following video about the neuromuscular junction. Remember that we have not yet talked about the nervous system and that we will learn more about neuron structure and action potentials next semester. For now, focus on the terms provided below.

Compare and contrast the roles of Na+ and Ca2+ in muscle contraction.

What questions do you still have about Part 2: The Neuromuscular Junction?

Part 3: The Art of Muscle Contraction

Watch the following video on muscle contraction. (Note: You may watch the whole thing, but the beginning is review. He'll start talking about skeletal muscle contraction at 1:45)As you watch, match the terms below with the best description.

Describe the relationship between tropomyosin, troponin, myosin, and actin

Ok - Let's talk more about ATP. Examine the picture below, focusing on Adenosine Triphosphate (ATP), Adenosine Diphosphate (ADP), and Phosphate (P).Which of the following statements about the role of ATP, P, and ADP in muscle contraction are accurate?

Think back to this simplified description of ATP hydrolysis that we saw the other day (left) and compare it to the more complex, accurate description on the right. Which of the following best describes ATP hydrolysis?

What questions do you still have about Part 3: The Art of Muscle Contraction

Part 4: Putting it All Together

WITHOUT LOOKING AT YOUR NOTES: Put the following steps of muscle contraction in the correct order. The order should go from before a contraction --> contraction

What is still confusing about the Sliding Filament Model?

Refer back to Section 10.2 or Section 10.3 of your textbook and fill in your confusion. How did the textbook help? What are you still confused about?

Refer back to Section 10.2 or Section 10.3 of your textbook and fill in your confusion.

How did the textbook help? What are you still confused about?

First, identify the following as true or false:

Myofibrils are smaller than sarcomeres.

Then, draw a picture justifying your answer.

The picture below displays a simplified version of a single sarcomere.

Match the terms with the correct letter on the diagram.

Watch the following video on muscle contraction.
(Note: You may watch the whole thing, but the beginning is review. He'll start talking about skeletal muscle contraction at 1:45)

As you watch, match the terms below with the best description.

Ok - Let's talk more about ATP. Examine the picture below, focusing on Adenosine Triphosphate (ATP), Adenosine Diphosphate (ADP), and Phosphate (P).

Which of the following statements about the role of ATP, P, and ADP in muscle contraction are accurate?

Think back to this simplified description of ATP hydrolysis that we saw the other day (left) and compare it to the more complex, accurate description on the right.

Which of the following best describes ATP hydrolysis?

Refer back to Section 10.2 or Section 10.3 of your textbook and fill in your confusion.

How did the textbook help? What are you still confused about?