BIO 7 EXAM 3

What is the role of tropomyosin in muscle contraction?

To prevent myosin from continuing to slide up the actin filament

_____________ moves _____________ off of the myosin binding sites on actin.

Troponin, tropomyosin

When the cross‐bridges bind to actin, they will pivot in such a manner to cause the actin filaments to slide. This pivoting action causes the actin filaments to slide __________.

close together

In order to make ATP (adenosine triphosphate) in muscles, creatine phosphate (CP) transfers __________ to adenosine diphosphate (ADP).

phosphate

The membrane around a muscle cell is called a __________.

sarcolemma

____________ Filament moves the _____________ Filament

thick, thin

Which of the following would be antagonistic to the biceps brachii?

triceps brachii

When muscle contracts upon stimulation, calcium ions bind to __________, which exposes the binding sites for the myosin cross‐bridges to attach to.

troponin

Each myosin head uses _________ to change shape.

1 ATP molecule

Which of the following statements is true regarding the structure of smooth muscle?

They consist of an irregular arrangement of actin and myosin.

Which of the following statements describe the function of smooth muscles?

They contract relatively slowly in a controlled manner.

______ leaves the sarcoplasmic reticulum and binds to __________ in the sarcomere.

Ca2+, Troponin

After the receptor is activated, _________ ion depolarizes the muscle fiber cell and travels through the ___________.

Na+ , T Tubules

2. What structure stores Ca2+ in the muscle fiber?

Sarcoplasmic reticulum

A __________ neuron releases the neurotransmitter that initiates skeletal muscle contraction

Somatic Motor (efferent) neuron

What is the role of acetylcholine in calcium release?

Stimulates cellular contraction by opening voltage-gated ion channels

Calcium ions are released from the sarcoplasmic reticulum to initiate muscle contraction and are reabsorbed upon muscle relaxation. Which of the following occurs if calcium ions are not completely reabsorbed?

The next muscle contraction will be greater than the previous muscle contraction.

Which of the following is accurate regarding Type I and Type II muscle fibers?

Type I fibers store much of their energy as triglycerides, whereas Type II fibers store energy as ATP or creatine phosphate

The binding sites for the cross‐bridges are located on __________.

actin

The troponin/tropomyosin complex is associated directly with which of the following filaments?

actin

Thin Filament is made up of _____________.

actin, troponin, tropomyosin

Lactic acid is NOT produced during which of the series of reactions?

aerobic respiration

Which of the following sets of reactions produce the most ATP for muscle contraction?

aerobic respiration

Lactic acid, a byproduct of cellular respiration, is typically produced during __________ respiration.

anaerobic

ATP can be made in muscles from stored glucose. In muscles, glucose is stored in the form of __________.

glycogen

Myosin cross‐bridges are extensions of __________.

myosin

Once myosin binds to actin, __________ heads change shape and slide the ________.

myosin, actin

The actin filaments are attached to the __________.

z disc