ADMS 2510 Lecture Notes - Lecture 9: Thylakoid, Spectroscopy, Microtubule

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sapphirecattle739

7 Mar 2016

School

York University

Department

Administrative Studies

Course

ADMS 2510

Professor

Douglas Kong

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ADMS 2510 Full Course Notes

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This test is for study purposes only and o o does not include all test topics the quesions are not a mirror of the test quesions. They possess color corresponding to the color of absorbed light: they possess delocalized electrons that absorb light energy and move to an excited state. D. it is characterized by a conjugated system: which of the following is not characterisic of bacteriorhodopsin, it is found in certain prokaryotes, it absorbs light energy. It is involved in certain types of photosynthesis but remember it is the reinal in the complex that absorbs light. The scienist proposes a series of hypotheses to explain the decline. Prevents dna damage resuling from uv light: prevents the formaion of uva and uvb in the skin, the change in free energy in a biochemical reacion, is always exergonic, is always endergonic, is the same as acivaion energy.

Related Questions

Chlorophyll is a pigment that absorbs specific wavelengths of light, and the absorption of that light leads to the passage of electrons to a higher energy state, where chemical energy can then be harvested from them. You would expect that a plant exposed to which color of light would produce the most photosynthesis?

Which color of light would you expect chlorophyll to absorb the least?

Most plants are green because....

chlorophyll absorbs green light well

chlorophyll does not absorb green light well

chlorophyll reflects green light well

both of the last two answers are correct

Thinking about the gases involved in respiration and photosynthesis, during the day, a plant is producing____ from respiration and releasing_____ from photosynthesis. But at night, a plant is only producing_______ from respiration.(spell your answers out completely).

Plants perform cellular respiration to produce.......

Which of the following is true about plants and cellular respiration?

plants perform cellular respiration only during the night

plants perform cellular respiration only during the day

plants perform cellular respiration during the night and day

plants do not perform cellular respiration

Which of the following is true regarding plants and photosynthesis?

plants perform photosynthesis only during the night

plants perform photosynthesis only during the day

plants perform photosynthesis during the night and day

plants do not perform photosynthesis

Is it possible for this plant to consistently do more cellular respiration than photosynthesis?

yes, plants use excess ATP for growth

yes, but only during winter months

not today, but fossil records shows they did in the past

no, plants can't consume food faster than they make it

Exercise #5: The Nervous system and Perception

Task #1: Color vision

Introduction

In the human retina, there are two kinds of light-sensitive cells: rods and cones. These cells are located on the outside of the retina, away from the vitreous humor and against the choroid layer, and are covered by a later of bipolar and ganglion cells as well as neurons. Light enters the posterior chamber through the lens and must pass through several cell layers before it is absorbed by the rods and cones.

Cones are involved in color vision at daylight intensities. Generator potentials in a cone excite one neuron, giving high-level resolution vision. Cones will not cause neural firing at low light intensities and are, therefore, nonfunctional at night.

Rods provoke black-and-white vision at low light intensities. A bipolar cell associates with several rods, so that generator potentials sum in their effect. This assures neuronal firing at low light intensities and provides a highly sensitive vision but with less resolution.

Receptor convergence. A ganglion cell, which receives input from a number of rods, spread out over the retina, cannot pinpoint the source of a light stimulus as well as a ganglion cell, which is stimulated by a single photoreceptor. In the case of a ganglion cell receiving the added input of several rods, light hitting any one of the rods can cause a neural spike in the ganglion cell, but the brain has no way to know which rod was excited. It is therefore harder to pinpoint the location of light stimuli on the retina when the stimulus is detected by rods (as compared to cones). The result is that our ability to see detail, or our resolving power, is considerably lower under dim light conditions than under bright light conditions.

Dark adaptation. If you go from a lighted area to a very dark room, you will not be able to see. After about ten minutes, however, you begin to be able to see again. This occurs because the rhodopsin pigment, which gets broken down when it absorbs light, is continually re-synthesized in the rods. When there is very little light, very little rhodopsin gets broken down and the amount of rhodopsin gradually builds up, making the rod much more sensitive to dim light.

When light strikes a receptor cell, it triggers a photo-chemical reaction that leads to neuronal firing. If a rod or cone receives high-intensity light, the visual pigments will be temporarily bleached and will not absorb any more light. Within a matter of a few seconds, enzyme systems in the cells will restore the visual pigment to its light-absorbing form. This can be easily demonstrated. If, after viewing a bright light, the eye is quickly shut or turned to a dark wall, the bright image will persist as a positive afterimage because the high generator potential causes the continued firing of neurons. If the eye is cast on a lighter background after a few seconds, a negative afterimage, or a dark image of the object will appear. This is because the still bleached cells are not receptive to the light coming from the light background.

According to the Young-Helmholtz theory of color vision, there are three types of cone cells, which respond respectively to red, green, and blue light.

All other colors are perceived as the brain interprets impulses coming from a mix of these receptors. If an object of one color is viewed for a long period of time at high light intensity, the cones for that color will become bleached. The afterimage of the object will be seen in the complementary color.

The Exercise 6 PowerPoint will demonstrate afterimages to you. Use the slide show option to project the square of red light on your entire screen in a dark room. After staring intensely at the square for 30 seconds or so, without shifting your gaze, click enter to change the slide to a soft white. Continue staring at the screen as the change is made. What do you see? What was the color of the afterimage?

Repeat this experiment using a blue square. Before doing the experiment, hypothesize what color the afterimage will be according to the Young-Helmholtz theory.

Hypothesis to be tested: (2 pts)

What did you see when the experiment was conducted? (2 pts)

Was you hypotheses accepted or rejected? (1 pt)

Explain the colors seen in these afterimages using the Young-Helmholtz theory. (5 pts)

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Photosynthesis Lab Report

Plant Structure and Function

Through the process called __________ plants convert lightenergy into

__________ energy. Record your answerbelow.

In which structure of the plant does photosynthesis occur?

What is the difference between xylem and phloem?

Based on lab, Exercise 1, what is the name and function of thestructure labeled with the letter âHâ?

Chloroplast

Based on Lab, Exercise 2, draw and label each part of thechloroplast. Sign, date and prepare an image of your drawing andinclude it with this lab report.

What part of the process of photosynthesis occurs in thethylakoid compartment?

What is the name and function of the structure labeled with theletter âEâ in Exercise 2?

Photosynthetic Products

What are the three products of photosynthesis?

What happens to the glucose that is not metabolizedimmediately?

In the test for starch, which tube demonstrated a positive testfor starch? How do you know?

Based on Lab, Exercise 3 explain why part of the leaf was amberin color.

Light Absorption

What pigment is used by plants to absorb light?

In the video demonstration in Exercise 4 what happens to thelight spectrum when a green filter is placed in front of the lightsource?

In step 3 of Exercise 4, which color was not absorbed by thespinach pigments?

Photosynthetic Pigments

What process is used in Exercise 5 to separate the plantpigments?

Look at the chromatogram results in Exercise 5. What color isreflected by chlorophyll a?

Which pigment reflected an orange color?

VI. Effect of Light and Temperature onPhotosynthesis

What was the conclusion of Blackmanâs first experiment on theeffect of light on photosynthesis?

In his second experiment, what effect did increasingtemperature have on the rate of photosynthesis?

Record the data from Exercise 6 below.

Lamp Distance	Temperature	Ave Bubble/min
75 cm
50 cm
25 cm

In the experiment in Exercise 6, what conclusion can be drawnabout the effect of light and temperature on rate ofphotosynthesis?

Summary Questions

Why do heterotrophs depend on autotrophs?

Name two reactants necessary for photosynthesis to occur.

How would the process of photosynthesis be affected if a planthad no stomata?

What tool is used to separate white light into differentwavelengths of color?

Explain why we see the color green on the leaves ofplants.

What color is absorbed the least by the petals on asunflower?

Photosynthesis consists of two phases. Which phase would beleast affected by living in an area where there are shorter daysand long periods of darkness?

How could air pollution affect food production and the priceyou pay for food at the supermarket?

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ADMS 2510 Lecture Notes - Lecture 9: Thylakoid, Spectroscopy, Microtubule

ADMS 2510 Full Course Notes

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