Concept Check 27.5 Bustamante

Concept check 27.5
1. Explain how muscles work in pairs in moving limbs.

Muscles are connected to bones by tendons. When one muscle contracts, it brings a bone and bends a joint. In order for the bone to go back, another muscle has to contract, thus working in pairs like the biceps and triceps.
2. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.

A muscle fiber is made up of one, multiple nuclei cell. This cell is composed of units called myofibrils. Each myofibril has small units of contraction called sarcomeres. 2 kinds of filaments, actin (thin filaments) and myosin (think filaments), form sarcomeres.
3. Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.

• Nervous system: the brain processes the views you capture, and makes your body and hand muscles respond to it. Also, it processes the stimuli given by the other hand and responds in how much to tighten the hand shake.
• Muscular system: it respond to nervous system by contracting and relaxing many muscles to move your arm and hand.
• Circulatory system: it provides nutrients and oxygen to the nerves and muscles in order for them to function and metabolize properly.

4. Explain how actin and myosin interact as a muscle cell contracts.

Myosin heads attach to the actin. When the heads bend, the overlapping between myosin and actin increases, thus shortening the sarcomere. When the muscle is relaxed, myosin and actin overlap less, lengthening the sarcomere. The various myosin heads detach and attach again, but not simultaneously, so that fibers do not relax.

Concept Check 27.5

1. Explain how muscles work in pairs in moving limbs.
The Muscles of the human body work in pairs. When one muscle relaxes the other one contracts. and viceversa.

2. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.
Muscle FIbers: They contain the nuclei.
Myofibrils: Contain bandles of smaller units.
Actin: The protain which makes the thinner filaments.
Myosin: The protain which makes the thicker filaments.
Sarcomere: The Muscle fibers.

3. Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.
You use you brain to coordinate you hand with your eye. The you use your nerves to feel the other person's hand. Finally your muscles allow you to move your hands and parts of the body.
4. Explain how actin and myosin interact as a muscle cell contracts.
They are both protains that make the filaments of the muscles.

1. Explain how muscles work in pairs in moving limbs.

For each skeletal muscle that is contracting, there is an opposing muscle—one that is relaxed but that can contract and pull the bone back in the opposite direction.
2. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.

consists of bundles of parallel muscle fibers along with a supply of nerves and blood vessels. Inside a muscle fiber are bundles of smaller units called myofibrils. A single myofibril consists of repeating units called sarcomeres. Each sarcomere is composed of two kinds of filaments, thin and thick. The thin filaments are composed of the protein actin and have a twisted, ropelike structure. The thick filaments are composed of the protein myosin and have bumplike projections called myosin heads.
3. Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.

Involves the cooperation of many of your body's organs, tissues, and cells.

4. Explain how actin and myosin interact as a muscle cell contracts.

In each mini-contraction (shown in Figure 27-18), myosin heads first bind to thin filaments. Next, the myosin heads bend, pulling the thin filaments toward the center of the sarcomere.

Explain how muscles work in pairs in moving limbs.

As one muscle contract the other muscle relaxes. Since muscles cannot push, only pull, and opposing motion is needed to return the bone to its original position.

2. Identify the structures that make up a skeletal muscle. Include these terms:
muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.

Muscle fiber: Long muscle cell that contains many nuclei.
Myofibrils: unit of muscle fiber made up of smaller units that contract (sarcomeres)
Sarcomere: unit of contraction in a muscle fiber Has 2 type of filaments, thin and thick.
Actin. Twisted thin filament in a muscle fiber.
Myosin: The thick filament of a sacromere. Has bump- like projections. called myosin heads.

3. Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.

First your eyes sense a person near and sends a message to your brain. The thinking part of your brain decides to initiate the handshake. The other regions of the brain sends a message though your nerves to the muscles. The response are coordinated contractions and relaxations in the muscles of the back, shoulder, forearms, upperarm and wrist. These muscles lift and extend the right bones in the correct sequence to extend the hand. At the end many muscles manipulate the 27 bones in your hand into place.

4. Explain how actin and myosin interact as a muscle cell contracts.

Myosin heads with the thin filaments interact to make muscle contraction. IN a mini contraction myosin heads first bind to thin filaments, then the myosin head bend pulling the thin filaments to the center of the sacromere, the ATP binds to each myosin head relicing it from the filament.

CONCEPT CHECK 27.5

1. Explain how muscles work in pairs in moving limbs.
Muscles cannot push only pull, so it works together with a pair. When a muscle is contracting, its opposing muscle is relaxed. This muscle has to contract and pull, so that it moves to the opposite direction. Ex) Biceps and triceps. When Biceps are contracted, triceps are relaxed, And vice verse.

2. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.
Muscle fiber: Long muscle cell that contains many nuclei. (cylindrical shape)
Myofibrils: Found inside a muscle fiber. Unit of muscle fiber made up of smaller units that contract (sarcomeres)
Sarcomere: A myofibril are repeating units called sarcomeres. Unit of contraction in a muscle fiber. Has 2 type of filaments, thin and thick.
Actin: The thin filament of sacromere. Composed of protein. Twisted thin filament in a muscle fiber.
Myosin: The thick filament of a sacromere. Composed of protein. Has bump- like projections. called myosin heads.

3. Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.
1st. Your eyes see the person, and send a message to your brain. The thinking side initiates the handshake, and sends message to muscles. There are coordinated contraction and relaxation in muscles: your back, shoulder, upper arm, forearm, and wrist. The muscles manipulate the 27 bones in your hand into place.

4. Explain how actin and myosin interact as a muscle cell contracts.
Myosin heads first attach to the thin filaments. Myosin heads bend, and pulls thin fillament in sacromere. ATP releases myosin head from thin filament. Myosin head is now free to attach at a new spot and further pull the thin filament along.

ISA ITURRALDE

1.Explain how muscles work in pairs in moving limbs.

• as one of the muscles contracts the other muscle realxes and this is working in pairs

2.Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.

1. muscles fiber:contain nuclei
2. myofibrils: it contains bandles for smaller units
3. actin:it is the protein that makes up thin filaments
4. Myiosin: protein that makes up thick filaments
5. Saromere: muscles fiber

3.Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.

1. Nerve, Muscle and bone system
2. the nerves feels the other persons hand, after that the muscles relax and contract and finally the bones keep the pieces together

4.Explain how actin and myosin interact as a muscle cell contracts.

both actin and myosin

Andres Jaramillo- 27.5

Concept check 27.51.

1.Explain how muscles work in pairs in moving limbs.

2.Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.

3.Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.

4.Explain how actin and myosin interact as a muscle cell contracts.

Answers

1.Muscles always work in pairs and while one relaxes the other one contracts.

2.muscle fiber: long cylindrical muscle cell that contain nuclei
myofibrils: bundles of smaller units
actin: protein that makes up filaments
myosin:protein that make up thick filaments
sarcomere: muscle fiber basic unit of action


3. Muscles, bones and nerves are involved in hand shaking.
First you use your brain to coordinate. The eyes notice the presence of the other individual. Then use your muscles to relax and contract, then your nerves feels a sensation. You use 5 muscles (back, shoulder, upper arm, forearm, and wrist) and 27 bones.


4. Both actin and Myosin are proteins that make up filaments in the muscles.

Concept check 27.5
1. Explain how muscles work in pairs in moving limbs.
as one muscle contracts the other relaxes and vice versa
2. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.
a muscle is made up of muscle fibers, muscle fibers are made up of myofibrils, these have sacromeres. sacromeres are made up of two types of filaments, thin (actin) and thick (myosin)
3. Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.
muscles, bones and nerves. your brain gives the message to give the hand shake. the muscles receive the order and the muscles contract and relax depending on the movement, and finally the muscles move with the bones to make the hand shake possible
4. Explain how actin and myosin interact as a muscle cell contracts.
myosin first binds thin filaments in each contraction. then the heads band to the center.

Concept check 27.5

Please read section 27.5 of the online Biology book on muscles. Take notes of the reading in your Health notebook. Post your answers to concept check 27.5 on the blog and provide constructive feedback to three other learners. Constructive feedback not only means you may agree with someone else's answers or ideas but as well how those ideas may open the doors to new learning opportunities.  Due date: Jan. 10, 2011

Concept check 27.5
1. Explain how muscles work in pairs in moving limbs.
2. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.
3. Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.
4. Explain how actin and myosin interact as a muscle cell contracts.