BIO 3303 Lecture Notes - Lecture 12: Everytime, Signal Transduction, Cilium

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rubytortoise417

8 Sep 2017

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Photoreceptors: transduction of energy from photons that wil result a change in membrane potential. 1st photoreceptors take photons and photo pigments withing the chromophre change conformation when it absorbs light, 2nd signal transfuction pathway causes the membrane potential to gradually change and neurotransmitters will be released causes localized graded potentials. Photopigment it is a protein within a chromophore that causes change in the conformation when it will absorb light. The conformation is a result from a protein cascade that leads to change in the membrane; it changes conformation when light hits it; triggers a cascade that released a graded potentials then nt release. Photoreceptive organs: are the strucutures that are involved in the specialization of light detection, endcode direction, intensity. The visible spectrum for us is visible lights. (be abe to give examples later on) It is a very small portion of the electromagnetic spectrum .

Related Questions

Please write a sentence or twohypothesis for the first question, then describe your reasoning inparagraph form for each question. Points will be rewarded accordingto best use of key vocabulary words and proper description.thanks!

1)Write a one-sentencehypothesis before you write an answer.

Many aquatic invertebrates suchas squid, lobster, and crayfish are capable of very rapid muscleactivity and body movement. They respond to stimuli such as touchjust as rapidly as do terrestrial vertebrates. These capabilitiesof some, but certainly not all, aquatic invertebrate animals occureven though the animals lack myelination of their nerveaxons. Terrestrial animals have myelin covering many of theiraxons.Explain how these fast-moving invertebrates can have rapidresponses to stimuli and rapid onset of muscle movement in thecomplete absence of myelination of their axons. Include adiscussion of the structure of their axons that allows such rapidactivity and explain how it works.

2)Do Not Write aHypothesis.

How do aquaticand marine invertebrates that employ external fertilization avoidtwo major problems %u2013 fertilization of one egg by more than onesperm and fertilization of an egg by a sperm from a closely relatedbut different species.

lavenderwoodchuck851

1/ G-proteins are a commonly found in cell signaling pathways, which of the following events normally activates a GTP-binding protein?

(a) GTP hydrolysis by the protein

(b)Activation of an upstream GTPase-activating protein

(c)Exchange GDP for GTP by the activation of an upstream guanine nucleotide exchange factor(GEF)

(d)Pi release after GTP hydrolysis

2/ Which of the following inactivates a G-protein?

(a) The Î² subunit exchanges its bound GDP for GTP.

(b) The GDT bound to the Î± subunit is hydrolyzed and forms GDP

(c)The Î± subunit exchanges its bound GDP for GTP.

(d) TheÎ²Î³ complex inactivates the G-protein

3/ Olfactory receptors where first hypothesized to be numerous receptor types that were able to recognize specific odorants. We now know that olfactory receptors are made up of ONE receptor family, which is one of the largest gene families know in the human genome. Which of the receptors below comprise the olfactory receptor family?

(a)RTK

(b) Delta-Notch

(d) Ion Channel Receptors

4/ Which of the following are possible responses a cell may have as a result of activation of a cell signaling pathway?

(a) Change in gene expression

(b) Alteration of activity of metabolic enzymes

(d) All of these

5/ Which of the following statements about the cytoskeleton is false?

(a) The cytoskeleton is made up of three types of protein filaments.

(b) The cytoskeleton controls the location of organelles in eukaryotic cells.

(d) The cytoskeleton of a cell can change in response to the environment.

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Examine the following proteins and determine how many domains each polypeptide has. (If there is more than one chain or model, only examine one.) List the residues in each domain (e.g. 17-98, 141-169), and classify each domain (as in part 1).

1. One subunit of human branched chain aminotransferase (4HBA)

2. Escherichia carbenicillin-binding protein (5ECB)

3. One subunit of the enterobacterial ligand-gated ion channel (6ELC)

C. Examine the following multimeric proteins and classify the symmetrical arrangement of the subunits (e.g. C2, C3, D2, helical, icosahedral). If the program asks you to âLoad __ modelsâ, just hit OK with whatever number it has by default. (Note that each model will load as a different layer.)

1. Nitrosomonas hydroxylamine oxidoreductase (7NHO)

2. Enterobacterial lectin (8EBL)

3. Enterobacterial ligand-gated ion channel (6ELC)

D. Examine the 2 pairs of proteins below. In each case, these are enzymes that catalyze the same reaction in different species. The question is: are they related or not? i.e. Are the structures essentially the same? Often you can get similar reactions from proteins that evolved from a common ancestor (e.g. trypsin and chymotrypsin). Sometimes the same reaction can be catalyzed by proteins with very different evolutionary origins and with very different structures (e.g. trypsin and subtilisin). Your job is to decide if these proteins have fundamentally different folds or if they have basically the same fold. Briefly justify your answer (â¤3 sentences).

Aldolase from an Archaea and a Bacillus (PR1A & PR1B)

Isochorismate synthase from a Proteobacterium and a Bacillus (PR2A & PR2B)

BIO 3303 Lecture Notes - Lecture 12: Everytime, Signal Transduction, Cilium

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