Ask Question, Ask an Expert

+1-415-315-9853

info@mywordsolution.com

Ask Biology Expert

1. The three components of the eukaryotic cytoskeleton are microtubules, microfilaments and intermediate filaments.

a) State the principle protein component of the microtubules, and briefly describe the structure of a microtubule.
b) Describe how microfilaments polymerize from their monomer components. Include a description of the protein component(,0) treadmilling, and the role of ATP and capping proteins.
c) The following proteins all interact with microfilaments: ezrin, ARP complex, cofilin, myosin, fimrin. Describe the functions of three of these proteins within the cell.
d) Give one ex of a protein that may form intermediate filaments and describe the type of structures that intermediate filaments produce.

2. a) Briefly describe the main differences between integral and peripheral membrane proteins in terms of their location and interactions with the lipid bilayer.
b) Describe the arrangement of secondary structural elements in one type of multipass transmembrane protein.
c) How can antibodies raised against segments of amino acid in a membrane protein be used to provide information on the structure of that protein?

3. a) Briefly describe how the core eukaryotic nucleosome is formed from its protein components and the location of the DNA strand, in relation to the nucleosome.
b) How is the local structure of chromatin maintained during genomic DNA replication?
c) Describe what occurs to nuclear DNA in a cell that has undergone apoptosis, and describe the characteristic pattern shown by DNA from an apoptotic cell, when it is examined by agarase gel electrophoresis.

4. a) List three ways in which mature mRNA differs from the primary transcript.
b) Which of the features of mature eukaryotic mRNA, identified in )a), influence the stability of mRNA and how?
c) Briefly describe what is meant by RNA editing, how this process can occur and how it affects the protein that the RNA encodes.

5. a) Briefly describe what is meant by the term 'growth cone.'
b) What effects do the molecules netrin and semaphorin have on the process of neurit outgrowth?
c) What type of molecules are cadherins, and what effect do they have on neurite outgrowth?
d) Describe how netrin, semaphorin and slit control the growth of the axons of commissural neurons across the midline and towards the brain during development.

6. a) Briefly describe the G2 checkpoint which is sensitive to DNA damage. Use diagrams as appropriate to describe how the activities of the phosphatase Cdc25 and kinase Weee1 play a role in the control of entry into M phase.
b) describe how the positive feedback loop in this checkpoint functions.
c) What are the two principal external causes of double-strand breaks in DNA?
d) Briefly outline two mechanisms by which double-strand breaks are repaired by a cell.

7. a) Give one ex of a cell-type that may be mobile within the tissues of an adult mammal, and describe how motility contributes to the normal function of that cell.
b) Define the term 'chemotaxis' and give one ex of a molecule that can induce chemotaxis.
c) describe with the aid of a labelled diagram how molecules that induce chemotaxis can act on a cell to cause its polarization. The diagram should include information on the receptor for the chemotactic molecule and the intracellular signals and events that follow activation of the receptor.

8. a) describe the difference between reactive oxygen species and free radicals, and give one ex of each.

b) What cellular process is the main source of free radicals in eukaryotes and where does it take place?
c) What biological molecules can be damaged by interaction with free radicals? Give one ex of the way that a free radical can interact with a biological molecule to change its structure.
d) describe the different between primary and secondary antioxidant defenses, giving one ex of each.

Biology, Academics

  • Category:- Biology
  • Reference No.:- M924249

Have any Question? 


Related Questions in Biology

1 identify five different mammalian species2 describe what

1. Identify five different mammalian species. 2. Describe what tissues regenerate. 3. Discuss if you believe that each of these mammals use the same or a different mechanism to regenerate tissues?

If instead of making an energy drink you come up with an

If instead of making an energy drink, you come up with an energy injection, how would that affect the ingredients you put into the shot? Think in terms of polarity and tonicity.

Which common characteristics is not shared by birds and

Which common characteristics is not shared by birds. and mammals? Breathing using lings Viviparity warm blooded nature.

1 keeping in mind that lying is stressful what externally

1. Keeping in mind that lying is stressful, what externally detectable signs might a lie detector identify, assuming it reliability? 2. What would be the effect on the circulatory system if a person received a massive do ...

Steroid hormones such as testosterone are derived from

Steroid hormones, such as testosterone, are derived from cholesterol. What type of macromolecule are they?

Frtilized grasslands diversity 6930 and richness

Fertilized grasslands: diversity = .6930 and richness = 4 Unfertilized grassland: diversity = .7075 and richness = 10 Answer the question by the following: 1. Which grassland has the higher species richness, and is it a ...

Genetics- epigeneticsread the below article if you think

Genetics- Epigenetics Read the below article. If you think that you've perceived any flaws, overstatements/unsupported conclusions, or if you were simply left wondering about experiments that could have been done but wer ...

Evidence into diabetic care practicebased on the summary of

Evidence into Diabetic Care Practice Based on the summary of research findings identified from the Evidence-Based Project-Paper on Diabetes that describes a new diagnostic tool or intervention for the treatment of diabet ...

Explain why the removal of great sharks poses a threat to

Explain why the removal of great sharks poses a threat to bay scallops on the Atlantic Coast of North America, despite the fact that large sharks do not feed on scallops. Include the concept of a trophic cascade in your ...

As we get older we are prone to many conditions that affect

As we get older we are prone to many conditions that affect our bones, muscles and nerves. In your opinion how can these conditions be prevented?

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

WalMart Identification of theory and critical discussion

Drawing on the prescribed text and/or relevant academic literature, produce a paper which discusses the nature of group

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro