photosynthesis notes - Biology Junction
identify each of the cell structures indicated in figure 7-7 and explain its role in the cell
Diversity of Microbial Metabolism - Textbook of …
About the time that the continents began to grow and began, Earth produced its first known glaciers, between 3.0 and 2.9 bya, although the full extent is unknown. It might have been an ice age or merely some mountain glaciation. The , and numerous competing hypotheses try to explain what produced them. Because the evidence is relatively thin, there is also controversy about the extent of Earth's ice ages. About 2.5 bya, the Sun was probably a little smaller and only about as bright as it is today, and Earth would have been a block of ice if not for the atmosphere’s carbon dioxide and methane that absorbed electromagnetic radiation, particularly in the . But life may well have been involved, particularly oxygenic photosynthesis, and it was almost certainly involved in Earth's first great ice age, which may have been a episode, and some pertinent dynamics follow.
It is unlikely that the syndrome resulting from the failure of an organ as complicated as the liver should be explicable in terms of a single metabolic component, but the similarity between hepatic failure and certain expressions of congenital hyperammonaemias suggests an important role of ammonia toxicity in the pathogenesis of the syndrome.
Question Bank of Biology Questions and Answers - 3
It can be helpful at this juncture to grasp the cumulative impact of , inventing , inventing , inventing that made possible, and inventing . Pound-for-pound, the complex organisms that began to dominate Earth’s ecosphere during the Cambrian Period consumed energy about 100,000 times as fast as the Sun produced it. Life on Earth is an incredibly energy-intensive phenomenon, powered by sunlight. In the end, only so much sunlight reaches Earth, and it has always been life’s primary limiting variable. Photosynthesis became more efficient, aerobic respiration was an order-of-magnitude leap in energy efficiency, the oxygenation of the atmosphere and oceans allowed animals to colonize land and ocean sediments and even fly, and life’s colonization of land allowed for a . Life could exploit new niches and even help create them, but the key innovations and pioneering were achieved long ago. If humanity attains the , new niches will arise, even of the , but all other creatures living on Earth have constraints, primarily energy constraints, which produce very real limits. Life on Earth has largely been a for several hundred million years, but the Cambrian Explosion was one of those halcyonic times when animal life had its greatest expansion, not built on the bones of a mass extinction so much as blazing new trails.
The Cambrian Explosion had several phases to it, with explosions of life and mass extinctions, and a general atmospheric oxygen rise accompanied it. Anoxic conditions coincided with extinctions. would not be that affected by what complex life was doing (although anaerobes were generally driven underground and into the seafloor), but the rise of complex life led to new ecosystems. Before the rise of animals, the seafloor was smooth and “stiff,” but burrowing animals had profound impact on seafloor ecosystems and may have played a prominent role in creating the ecosystems themselves. Corals created new ecosystems, as life terraformed Earth.
Answer questions asked by users of Biology Questions and Answers.
Because of the central role of ATP in energy-generating metabolism,expect to see its involvement as a coenzyme in most energy-producingprocessesin cells.
Function and Equation for Respiration
1. Click on the following links and use the information provided to write a definition of cellular respiration in your own words.2. Identify which living things carry out the process of respiration.3. Write the chemical equation for cellular respiration. Label the reactants and products. Where have you seen something like this equation before? Explain.4. How does the equation for cellular respiration compare with the equation for photosynthesis?5. What is ATP? Why is it an important product of cellular respiration?6. Using the same link from #5, write the chemical equation for the breakdown of ATP. Does the reaction release energy (exothermic) or absorb energy (endothermic)? Support your answer.7. Write the equation for the synthesis of ATP. Does the reaction release energy (exothermic) or absorb energy (endothermic)? Support your answer.
Use the following link to answer questions 8-10:
8. What is the main site of respiration in the cell?9. Make a sketch of the respiration organelle and label its parts.10. What energy molecules are produced in this respiration organelle?11. What is the difference between aerobic and anaerobic cellular respiration?12. Click on the �Cellular respiration� link and scroll down to fermentation. What is lactic acid fermentation? Where does it occur?13. What does a build up of lactic acid cause?14. What is alcoholic fermentation?15. In what industry is alcoholic fermentation important?16. Which produces the larger amount of energy � aerobic or anaerobic respiration? Support your answer with information from the reading.
17. Write a summary of cellular respiration. In your response:
AQA | Biology | Subject content | Biological molecules
Opportunities for skills development
ATP and Energy Storage
Understanding Our Bodies: Insulin | Nutrition …
Interactive animation showing how ATP functions like a rechargeable battery in the transfer of energy.
Great Pacific Media - The Basics of Biology DVD Series | …
by Theresa Knapp Holtzclaw
Oxygen is a chemical element with symbol O and atomic number 8
Some bacteria use Photosystem I and some use Photosystem II. More than two bya, and maybe more than three bya, cyanobacteria used both, and a miraculous instance of innovation tied them together. were then used to strip electrons from water. Although the issue is still controversial regarding when it happened and how, that instance of cyanobacteria's using manganese to strip electrons from water is responsible for oxygenic photosynthesis. It seems that some enzymes that use manganese may have been "drafted" into forming the manganese cluster responsible for splitting water in oxygenic photosynthesis. Water is not an easy molecule to strip an electron from, a single cyanobacterium seems to have “stumbled” into it, and it probably happened only . Once an electron was stripped away from water in Photosystem I, then stripping away a proton (a hydrogen nucleus) essentially removed one hydrogen atom from the water molecule. That proton was then used to drive a “turbine” that manufactures ATP, and wonderful show how those protons drive that enzyme turbine (). Oxygen is a waste product of that innovative ATP factory.
Energy and the Human Journey: Where We Have Been; …
As with enzymes, the molecules used in biological processes are often huge and complex, but ATP energy drives all processes and that energy came from either potential chemical energy in Earth’s interior or sunlight, but even chemosynthetic organisms rely on sunlight to provide their energy. The Sun thus powers all life on Earth. The cycles that capture energy (photosynthesis or chemosynthesis) or produce it (fermentation or respiration) generally have many steps in them, and some cycles can run backwards, such as the . Below is a diagram of the citric acid (Krebs) cycle. (Source: Wikimedia Commons)
Sunlight nourishes plant life by triggering photosynthesis
During that “,” , , and the rise of grazing and predation had eonic significance. While many critical events in life’s history were unique, one that is not is multicellularity, , and some prokaryotes have multicellular structures, some even with specialized organisms forming colonies. There are , but the primary advantage was size, which would become important in the coming eon of complex life. The rise of complex life might have happened faster than the billion years or so after the basic foundation was set (the complex cell, oxygenic photosynthesis), but geophysical and geochemical processes had their impacts. Perhaps most importantly, the oceans probably did not get oxygenated until just before complex life appeared, as they were sulfidic from 1.8 bya to 700 mya. Atmospheric oxygen is currently thought to have remained at only a few percent at most until about 850 mya, although there are recent arguments that it remained low until only about 420 mya, when large animals began to appear and animals began to colonize land. Just as the atmospheric oxygen content began to rise, then came the biggest ice age in Earth’s history, which probably played a major role in the rise of complex life.
"I have always been impressed by the quick turnaround and your thoroughness. Easily the most professional essay writing service on the web."
"Your assistance and the first class service is much appreciated. My essay reads so well and without your help I'm sure I would have been marked down again on grammar and syntax."
"Thanks again for your excellent work with my assignments. No doubts you're true experts at what you do and very approachable."
"Very professional, cheap and friendly service. Thanks for writing two important essays for me, I wouldn't have written it myself because of the tight deadline."
"Thanks for your cautious eye, attention to detail and overall superb service. Thanks to you, now I am confident that I can submit my term paper on time."
"Thank you for the GREAT work you have done. Just wanted to tell that I'm very happy with my essay and will get back with more assignments soon."