Chapter 5, Problem 18DAP

(a)

Summary Introduction

To draw: A diagram showing what a head-antibody-myosin complex might look like at the molecular level.

Introduction:

Antibodies are the Y-shaped proteins which provide immunity to the body by neutralizing antigens such as bacteria and virus. They are also known as immunoglobulins. An antigen is a foreign particle that induces the production of antibodies. These protein structures are the three-dimensional arrangement of atoms in a peptide chain.

(b)

Summary Introduction

To determine: The reason for the requirement of ATP for the beads to move along the actin fibers.

Introduction:

Adenosine triphosphate (ATP) is the energy currency of the cells that are produced during glucose metabolism. Actin proteins are the cytoskeletal proteins that are usually involved in the synthesis of microfilaments.

(c)

Summary Introduction

To determine: The reason for the failure of experiment if antibodies used were bound to the part of S1 and, if antibodies were bound to actin.

Introduction:

Myosins are the muscle proteins that carry out the muscle contraction and provide a wide range of motility in humans and other animals. Myosin proteins are known to interact with the actin fibers for motility processes. Antibodies are the Y-shaped proteins which provide immunity to the body by neutralizing antigens such as bacteria ad virus.

(d)

Summary Introduction

To determine: Why might trypsin attack the specific single peptide bond first rather than other peptide bonds in myosin.

Introduction:

Heavy meromyosin (HMM) and short heavy meromyosin (SHMM) are the two products of the digestion of the meromyosin. Meromyosin proteins can be digested by using trypsin in the process called proteolysis. Meromyosin is a part of the myosin protein These together form the muscle fiber called sacromere.

(e)

Summary Introduction

To determine: The model (S1 or hinge) that is consistent with the results observed in subpart (d).

Introduction:

The S1 fragment in the myosin acts as a motor domain and is involved in the contraction of the muscle. Hinge region is the region where cleavage with papain separates the immunoglobulin in two portions Fab (antigen-binding) portion and Fc (crystallizable fragment). Thehe region where they get separated known as hinge region.

(f)

Summary Introduction

To provide: A possible explanation for the increased speed of the beads with increasing myosin density.

Introduction:

The beads that are involved in the bead-antibody-myosin complexes are coated with the myosin and move along with the actin fiber that are associated with the myosin. Myosins are the muscle proteins that carry out the muscle contraction and provide a wide range of motility in humans and other animals.

(g)

Summary Introduction

To provide: A possible explanation for the plateauing of the speed of the beads at high myosin density.

Introduction:

Myosins are the muscle proteins that carry out the muscle contraction and provide a wide range of motility in humans and other animals. The beads that are involved in the bead-antibody-myosin complexes are coated with the myosin and move along with the actin fiber that are associated with the myosin.

(h)

Summary Introduction

To determine: The reason why SHMM was still capable of moving beads along the actin fibers.

Introduction:

Short heavy meromyosin (SHMM) and heavy meromyosin (HMM) is a product of digestion of meromyosin by the trypsin enzyme. Meromyosin is part of the myosin protein. Myosin is the muscle protein that along with actin involved in the muscle contraction.

(i)

Summary Introduction

To provide: A suitable explanation of the protein that remains intact and functional even though the polypeptide backbone has been cleaved and is no longer continuous.

Introduction:

Proteins are the biomolecules that are composed of amino acids. Proteins are the end products of gene expression. They are the structural elements of the body muscles. Proteins have four types of structure; primary, secondary, tertiary, and quaternary structure.