plant photosynthesis Essay

Submitted By freetrial23
Words: 825
Pages: 4
Open Document
Lab Exercise
DNA Extraction
10/30/13

DNA in all organisms is found primarily in chromosomes. Eukaryotic cells, like those found in humans, contain several linear chromosomes. Prokaryotic cells, such as bacteria, contain one large circular chromosome.

DNA is composed of building blocks called nucleotides, each made up of a five-carbon sugar (deoxyribose), a phosphate group, and a nitrogenous base. The four kinds of nucleotides differ only in their nitrogenous bases. It is the nucleotides and their bonding pattern that give DNA its unique characteristics and functions. Structurally, DNA contains two long strands of bonded nucleotides. These strands run in opposite directions. The two long strands are connected by hydrogen bonding between the nitrogen bases of the nucleotides (A-T and C-G). Each bonded pair of nucleotides is called a base pair. An average gene consists of a sequence of approximately 3000 base pairs.

The functional units of DNA, the genes, code for polypeptides which serve countless functions for the cell. Without proteins (for example, enzymes), the chemical reactions that make up a cell’s metabolism could not proceed in a timely manner and the cell would die. Bacterial chromosomes contain approximately 3000 genes. Humans, on the other hand, contain about 20,000-25,000 genes in each of their cells. If all of the DNA in all of the cells of a human were stretched end to end, it would form a ladder 100 billion kilometers (you could climb to the sun and back 300 times).

Today, you will extract DNA from the bacterium Micrococcus luteus. The first step is to lyse (burst) the M. luteus cells to release the DNA into the solution. In order to do this, a detergent used in laundry products called SDS (sodium dodecyl sulfate) is used to degrade lipids in the bacterial cell membrane. When the cell membrane is damaged, the cell lyses, releasing the cytoplasm’s contents into the solution. This causes the solution to become viscous (thick) due to the long strands of DNA that are no longer as tightly coiled as they were in the cell. Along with DNA, enzymes and other proteins are released. Because enzymes harmful to free DNA must be destroyed, the solution is heated (proteins denature or lose their functional shape at 60-650C). DNA also denatures when heated but only when the temperature reaches 800C.

Cold ethanol, an alcohol, will then be added. DNA is insoluble in alcohol and will precipitate (come out of solution) when it comes in contact with ethanol. A spooling rod is used to remove the DNA. By slowly rotating the rod in the solution, the DNA will attach and coil around it.

Because DNA is long and thin, it can be mechanically broken quite easily.
Be extremely gentle at all time.

Materials: per group of 4

1 tube of freeze dried M. luteus bacterial suspension solution (share bottle with other groups) SDS (sodium dodecyl sulfate) 1ml pipet and pipet pump two 5ml pipet and pipet pump 1 spooling rod (glass rod) 1 large test tube containing 20ml of 95% ethanol, refrigerated test tube rack hot water bath (60-650 C)

Procedure:

1. Pipet 5ml bacterial suspension medium into the test tube containing freeze-dried M. luteus
2. Gently rotate the test tube between your palms for approximately 5 minutes until the bacteria go into suspension.
3. Pipet 1ml SDS into the suspension.
4. Again gently rotate the tube between your palms several times over a 5 minute period.
5. Place the tube in a 60-650C water bath for 30 minutes.
6. After 30 minutes in the water bath, remove tube and allow to cool to room temperature.
7. Carefully lower the spooling rod (glass rod) into the tube.
8. Tip tube at 450 angle. Keep holding the tube at this angle until step 10.
Show More

Related Documents: plant photosynthesis Essay

Plant: Photosynthesis and Leaf Essay

Photosynthesis is a process that is used by plants; for this process to happen we need, energy from the sunlight (or light source) is absorbed by chloroplasts (the green substance in the chlorophyll). Carbon dioxide diffuses into the leaves, goes from a high area of carbon dioxide, to a low area of carbon dioxide. Water enters the plant by moving through the roots, up the stem and through the rest of the plants. All this allows glucose to produce between the reaction of carbon dioxide and water…

Words 327 - Pages 2

The Plants Need Ip As Energy To Realize The Photosynthesis

Bio 101 Homework Chapter 5 Multiple Choice 1. The plants need ATP as energy to realize the photosynthesis. 2. Photosynthesis is an example of an exergonic; light energy is captured by pigment molecule chemical reaction because endergonic; the reactions occur inside a cell. 3. The evolution of photosynthesis resulted in an increase in the amount of O2 in the atmosphere. 4. A plan appears green because it contains chloroplasts and the chlorophyll a absorbs ultraviolet light. 5…

Words 841 - Pages 4

Bio Notes Essay

BIOLOGY 2 Unit B2.3 Photosynthesis Know that all green plants and algae use light energy to make their own food. Know that all green plants and algae obtain the raw materials they need to make this food from the air and the soil. Know that the conditions in which plants are grown can be changed to promote growth. You should be able to use your skills, knowledge and understanding to be able to: interpret data showing how factors affect the rate of photosynthesis evaluate the benefits…

Words 445 - Pages 2

Essay on Biology Factors that affect the rate of Photosynthesis Practice Coursework

rate of Photosynthesis Aim To investigate and identify the factors that affect the rate at which photosynthesis happens. Introduction Photosynthesis is a series of chemical reactions that uses energy from sunlight to produce food. The product or ‘food’ is Glucose which is a sugar, photosynthesis happens in the cells in green parts of plants, for example in leaf cells. Photosynthesis can also occur in some microorganisms, for example phytoplankton. Chlorophyll is needed for photosynthesis, it is a…

Words 1145 - Pages 5

Photosynthesis And Respiration Essay

Photosynthesis and Respiration By:Ramiro Garcia Through many years of school and history we have thought of Photosynthesis as two opposite things, but they actually can’t work without each other. So in this essay we will be comparing and contrasting photosynthesis and respiration. Photosynthesis is a process used by plants and other organisms to convert light energy, normally from the Sun, into chemical energy that can be later released to fuel the organisms' activities. During photosynthesis there is a two­stage process…

Words 439 - Pages 2

Investigating A Factor That Affects The Essay

Investigating a factor that affects the rate of photosynthesis Photosynthesis is the chemical change which happens in the leaves of green plants. It is the first step towards making food, during this reaction; carbon dioxide and water are converted into glucose and oxygen. The reaction requires light energy, which is absorbed by a green substance called chlorophyll. Photosynthesis takes place in leaf cells. These contain chloroplasts, which are tiny objects containing chlorophyll. carbon dioxide…

Words 867 - Pages 4

Essay about Photosynthesis and Light Intensity

Photosynthesis Photosynthesis is the chemical change which happens in the leaves of green plants. It is the first step towards making food - not just for plants but ultimately every animal on the planet. During this reaction, carbon dioxide and water are converted into glucose and oxygen. The reaction requires light energy, which is absorbed by green stuff called chlorophyll. Photosynthesis takes place in leaf cells. These contain chloroplasts, which are tiny objects containing chlorophyll.…

Words 340 - Pages 2

Biology Questions Essays

Photosynthesis Lab 1. The rate of reaction was negative, meaning that the reaction that occurred was endergonic. It absorbed more energy than it released for the reaction to take place. Inside the bio chambers, the amount of carbon dioxide was decreasing which in turn made the reaction a negative number. 2. According to the data, photosynthesis was occurring in the leaves. 3. When the amount of heat on the plant increases, the amount of production from the carbon dioxide decreased. 4. The…

Words 660 - Pages 3

Essay on Photosynthesis: Photosynthesis and Photosynthesis Overview- Photosynthesis

Photosynthesis Overview- Photosynthesis is the process by which organisms use solar energy to make sugar and oxygen (nutrient molecules) from carbon dioxide and water (PimaCommunityCollege). The chemical equation of this process is: carbon dioxide + water =light energy=> glucose + oxygen 6CO2 + 6H2O =light energy=> C6H12O6 + 6O2, or Six molecules of carbon dioxide plus six molecules of water produce one molecule of sugar plus six molecules of oxygen. The two stages of photosynthesis: The…

Words 1291 - Pages 6

Essay on Biology in world

intensity affect the rate of photosynthesis? Background Information: Photosynthesis is a used by plants and other organisms, this process converts natural light energy, usually from the sun to chemical energy which can be then released to fuel that plant or other organisms. The organism absorbs the light energy, water, minerals and carbon dioxide in order to then produce glucose, which is like ‘food’ to the organism. Throughout this process oxygen is also produced by the plant, this oxygen is then released…

Words 1389 - Pages 6