bio notes

atmosphere

.03%carbon, 78%nitrogen, 21%oxygen, argon .9%

where in plants does 1.photosynthesis occur? 2.gas exchange (O2 CO2)

1 in leaves, in mesophyl 2.stomata

Net energy balance is an important measure because it allows for comparison of biofuels based on the

1) Energy required to manufacture each biofuel 2) Energy produced by each biofuel

Thylakoids...

1. Are assembled into stacks. 2.The space surrounding thylakoids is called stroma. 3.Thylakoids contain chlorophyll.

nitrogen fixation back into nitrogen gas process

1. ammonification- converts nitrogenous waste from living animals or from the remains of dead animals into ammonium (NH4+ ) by certain bacteria and fungi. 2.nitrification-this ammonium is then converted to nitrites (NO2−) by nitrifying bacteria, such as Nitrosomonas, through nitrification 3.denitrification-whereby bacteria, such as Pseudomonas and Clostridium, convert the nitrates into nitrogen gas, thus allowing it to re-enter the atmosphere.

human activity can release nitrogen into the environment by 2 means

1. combustion of fossil fuels 2.Artifical fertilizers

photon

1. light energy travels until it reaches a molecule of chlorophyll. 2.causes an electron in the chlorophyll to become "excited."

reduction reaction

1.ATP and NADPH use their stored energy to convert the three-carbon compound, 3-PGA, into another three-carbon compound called G3P 2.It involves the gain of electrons 3 The molecules of ADP and NAD+, resulting from the reduction reaction, return to the light-dependent reactions to be re-energized.

Starting with carbon dioxide in the air, put the following steps in order to trace the path of carbon through the slow carbon cycle:

1.Carbon is fixed by phytoplankton (photosynthetic marine organisms) through photosynthesis 2.Phytoplankton die and become fossilized 3.Fossil fuels are harvested 4.Carbon is released into the atmosphere through combustion

Select all of the ways you could have acquired nitrogen that is now in your proteins, DNA, and RNA:

1.From plants that acquired nitrogen from a mutualistic relationship with bacteria 2.From animals that ate plants that took up ammonia from the soil

Put the following steps in order to trace the path of nitrogen into a protein in the turkey you ate for Thanksgiving:

1.Lightning strikes, forming ammonia and nitrates 2.Usable forms of nitrogen are absorbed from soil by plants 3.Worms feed on decaying plant matter 4.The turkey acquires nitrogen by eating a decomposer

the light-dependent reactions

1.Purpose is to convert light energy into chemical energy. 2.Release oxygen from the hydrolysis of water as a byproduct.

carbon fixation

1.RuBisCO catalyzes a reaction between CO2 and RuBP, which forms a six-carbon compound that is immediately converted into two three-carbon compounds. 2. CO2 is "fixed" from its inorganic form into organic molecules.

A potato is left outside and decays gradually. One of the main substances in the potato is the starch amylose (C6H10O5). What happens to the carbon atoms in the amylose molecules as the potato decays?

1.Some of the atoms are incorporated into carbon dioxide 2.Some of the atoms are transformed by decomposers to form other organic molecules that make up their bodies

Describe the pathway of energy in light-dependent reactions.

1.The energy is present initially as light. 2.A photon of light hits chlorophyll, causing an electron to be energized. 3.The free electron travels through the electron transport chain, and the energy of the electron is used to pump hydrogen ions into the thylakoid space, transferring the energy into the electrochemical gradient. 4.The energy of the electrochemical gradient is used to power ATP synthase, and the energy is transferred into a bond in the ATP molecule. 5. In addition, energy from another photon can be used to create a high-energy bond in the molecule NADPH.

sedimentaion

1.any inanimate solids which are drifting in the oceans will slowly drop to the sea floor 2. The solids eventually become a part of the sediments on the ocean bed 3. solids can be dead organic matter or limestone

in all autotrophic eukaryotes( plants & algae) 1.photosynthesis occurs

1.chloroplast inside is chlorophyll, a pigment (a molecule that absorbs light) through which the entire process of photosynthesis begins.)

photosynthesis

1.converts solar energy into chemical energy. 2.It then is used to build carb molecules 3.The energy used to hold these molecules together is released when an organism breaks down food. 4.Cells then use this energy to perform work, such as cellular respiration.

water cycle

1.evaporation and sublimation 2.condensation and precipitation 3.subsurface water flow 4.surface runoff and snowmelt 5.streamflow

Once carbon enters a plant, it can

1.exit the plant as CO2 2.Become a part of the plant cell walls, protein, and fat 3.Be consumed by an insect feeding on the plant and become part of the insect's body

The carbon cycle is most easily studied as two interconnected subcycles

1.one dealing with rapid carbon exchange among living organisms 2.the other dealing with the long-term cycling of carbon through geologic processes

process of photosynthesis

1.provides most of the energy required by living things on earth 2. results in the release of oxygen into the atmosphere

Photosynthesis takes place in two stages:

1.the light-dependent reactions 2. the Calvin cycle.

Ethanol is inferior compared to many energy sources because it has only:

7 bonds that can be changed by cellular respiration or combustion to release energy

Put the following steps in order according to how light energy gets converted to chemical energy during photosynthesis

A 1.Light energy is absorbed by chlorophyll E 2.Chlorophyll is "excited," freeing up an electron M 3.Electrons move in a way that allows ATP(energy) to be generated F 4.ATP is formed and can be used to power metabolic processes

carbon cycle: biomass

All living things are made up of organic compounds which are very rich in carbon

Plants acquire nitrogen from:

Ammonium (NH4+) from bacteria and Ammonium (NH4+) from fertilizers

RuBisCO is the key enzyme for carbon fixation because it:

Attaches carbon dioxide to a molecule containing 5 carbons

Which of the following statements about the nitrogen cycle is false? a) Ammonification converts organic nitrogenous matter from living organisms into ammonium (NH4+). b) Denitrification by bacteria converts nitrates (NO3-) to nitrogen gas (N2). c) Nitrification by bacteria converts nitrates (NO3-) to nitrites (NO2-). d) Nitrogen fixing bacteria convert nitrogen gas (N2) into organic compounds.

C

Carbon Cycle picture

Carbon dioxide gas exists in the atmosphere and is dissolved in water. Photosynthesis converts carbon dioxide gas to organic carbon, and respiration cycles the organic carbon back into carbon dioxide gas. Long-term storage of organic carbon occurs when matter from living organisms is buried deep underground and becomes fossilized. Volcanic activity and, more recently, human emissions bring this stored carbon back into the carbon cycle

biogeochemical carbon cycle

Carbon is stored for long periods in what are known as carbon reservoirs, which include the atmosphere, bodies of liquid water (mostly oceans), ocean sediment, soil, rocks (including fossil fuels), and Earth's interior.

What would happen to the carbon cycle if all decomposers suddenly died and were not replenished?

Carbon would accumulate in organic matter

What would happen to the fast carbon cycle if all decomposers suddenly died and were not replenished?

Carbon would accumulate in organic matter

Looking at this figure from Hill et al. 2006, you could conclude that:

Corn grain ethanol produces more green house gas (GHG) emissions per net energy balance than soybean biodiesel.

One strategy for reducing the need for application of fertilizer is to plant legumes such as alfalfa and non-legume plants such as corn in alternating years. This allows:

Corn to utilize nitrogen that was fixed by bacteria in the alfalfa

The Keeling curve depicted here has an annual cycle. What is the primary cause of this cycle?

Fluctuations in amount of carbon being fixed by plants across seasons

What is the molecule that leaves the Calvin cycle to be converted into glucose?

G3P

The washing of fertilizer into bodies of water can lead to all of the following EXCEPT:

Higher concentrations of nitrogen in the atmosphere

phosphorus cycle

In nature, phosphorus exists as the phosphate ion (PO43-). Weathering of rocks and volcanic activity releases phosphate into the soil, water, and air, where it becomes available to terrestrial food webs. Phosphate enters the oceans in surface runoff, groundwater flow, and river flow. Phosphate dissolved in ocean water cycles into marine food webs. Some phosphate from the marine food webs falls to the ocean floor, where it forms sediment.

A mature maple tree can have a mass of 1 ton or more (dry biomass, after removing the water), yet it starts from a seed that weighs less than 1 gram. Which of the following processes contributes the most to this huge increase in biomass?

Incorporation of CO2 gas from the air by green leaves

A mature maple tree can have a mass of one ton or more (dry biomass, after removing the water), yet it starts from a seed that weighs less than one gram. Which of the following processes contributes the most to this huge increase in biomass?

Incorporation of CO2 gas from the atmosphere into molecules by the leaves

On March 10, 2004, National Public Radio reported that "forests in a remote part of the Amazon are suddenly growing like teenagers in a growth spurt." Though, the radio report added, "This shouldn't be happening in old, mature forests." This unexpected growth could be caused by:

Increased levels of carbon dioxide such that the forests can conduct more photosynthesis

Calvin cycle

It takes place in the stroma. The chemical energy given by the light-dependent reactions, captures carbon in carbon dioxide molecules and the subsequent assembly of sugar molecules.

On a hot, dry day, plants close their stomata to conserve water. What impact will this have on photosynthesis?

It will reduce it because less carbon dioxide will be available

Considering the global carbon cycle, where is the largest reservoir of carbon?

Lithosphere rocks

nitrogen cycle

Nitrogen enters the living world from the atmosphere through nitrogen-fixing bacteria. This nitrogen and nitrogenous waste from animals is then processed back into gaseous nitrogen by soil bacteria, which also supply terrestrial food webs with the organic nitrogen they need.

nitrogen

Nitrogen enters the living world via free-living and symbiotic bacteria, which incorporate nitrogen into their macromolecules through nitrogen fixation Nitrogen fixation is eventually converted from organic nitrogen back into nitrogen gas by bacteria.

Fertilizers increase plant growth by providing:

Nitrogen that can be taken up by plants

Which part of the Calvin cycle would be affected if a cell could not produce the enzyme RuBisCO?

None of the cycle could take place, because RuBisCO is essential in fixing carbon dioxide. Specifically, RuBisCO catalyzes the reaction between carbon dioxide and RuBP at the start of the cycle.

Fossil fuels are considered part of the "rock" pool of carbon on Earth. Burning fossil fuels moves that carbon into the atmosphere. Increased carbon in the atmosphere can lead to increased carbon:

On land and In the ocean

Carbon exists in the atmosphere. It could have come from all of the following sources EXCEPT: a) Cellular respiration by plants and animals b) Burning of biofuels c) Burning of fossil fuels d) Photosynthesis by plants

Photosynthesis by plants

Explain the reciprocal nature of the net chemical reactions for photosynthesis and respiration.

Photosynthesis takes the energy of sunlight and combines water and carbon dioxide to produce sugar and oxygen as a waste product. The reactions of respiration take sugar and consume oxygen to break it down into carbon dioxide and water, releasing energy. Thus, the reactants of photosynthesis are the products of respiration, and vice versa.

The light-dependent reactions begin in a grouping of pigment molecules and proteins called a photosystem.

Photosystems exist in the membranes of thylakoids. A pigment molecule in the photosystem absorbs one photon, a quantity or "packet" of light energy, at a time.

Which of the following is the most probable sequence of events when fertilizer runoff reaches a bay?

Phytoplankton population increases, decomposer population increases, decomposers consume oxygen via cellular respiration, fish and shellfish populations decrease because of lack of oxygen

Which process results in flux of carbon dioxide OUT OF the atmosphere:

Planting trees

For plants, the total amount of carbon gained by photosynthesis must be greater than that respired over their lifetime because...

Plants need carbon to grow and therefore must take in more than they lose

SATURATED FAT AND GLUCOSE MOLECULE Which molecule will yield more energy when combusted?

Saturated fat because energy is release when carbon switches from bonding with hydrogen to bonding with oxygen

The largest carbon reservoir on the planet is:

Sediment, including limestone

sulfur cycle

Sulfur dioxide from the atmosphere becomes available to terrestrial and marine ecosystems when it is dissolved in precipitation as weak sulfuric acid or when it falls directly to Earth as fallout. Weathering of rocks also makes sulfates available to terrestrial ecosystems. Decomposition of living organisms returns sulfates to the ocean, soil, and atmosphere.

Biosphere II is a huge dome-covered self-contained structure located outside Tucson, Arizona. Biosphere II was built to try to duplicate Earth's biosphere and ecosystems in miniature and to use the information gained from the experiment to help design similar habitats on the Moon and Mars. The habitat contained small versions of many of Earth's ecosystems, including an ocean with a coral reef, mangrove wetlands, a grassland, a desert, an agricultural system, and a human habitat. Eight men and women were sealed inside the habitat for a proposed two-year stay. The air, water, and food for the "biospherians" all came from inside the sealed habitat, and their only contact with the outside was through computers and telephones. Before the two years were up, however, the experiment failed. Supplemental oxygen was pumped into the facility and food supplies were provided through the airlocks. What caused the failure of the experiment? It was traced to nutrient pollution. The soil in some of the biosphere ecosystems was unusually rich in nutrients. These excess nutrients caused a huge population explosion in decomposer bacteria, which led to oxygen depletion. How could a population explosion of bacteria lead to oxygen depletion?

The excess consumers used the oxygen for cell respiration.

A loaf of bread was left uncovered for two weeks on a scale measuring its mass. Mold grew on it, decomposing the bread. Assuming that the bread did not dry out, which of the following is a reasonable prediction of the weight of the bread and mold together?

The mass decreases as the mold converts the bread into biomass and gases.

Imagine you leave a piece of bread out on the counter. After a week, you check back and it's moldy. How does the mass of the moldy bread compare to the mass of the original piece of bread?

The moldy bread has less mass

regeneration

The remaining G3P molecules regenerate RuBP, which enables the system to prepare for the carbon-fixation step. ATP is also used in the regeneration of RuBP

Lipids in soybean are typically found in the form of fatty acids linked to glycerol (depicted in this image). Which of the following statements accurately describes the amount of energy that can be harvested from this lipid?

The same amount of energy can be harvested from this lipid regardless of whether this occurs by combustion or cellular respiration

Where do plants get the sugar to run and build their bodies?

They make their own sugars internally, mainly from gas absorbed from the air.

What is the overall purpose of the light reactions in photosynthesis?

To convert solar energy into chemical energy that cells can use to do work.

water cycle picture

Water from the land and oceans enters the atmosphere by evaporation or sublimation, where it condenses into clouds and falls as rain or snow. Precipitated water may enter freshwater bodies or infiltrate the soil. The cycle is complete when surface or groundwater reenters the ocean

photoautotrophs (certain plants & bacteria)

a type of autotroph that uses sunlight and carbon from carbon dioxide to make chemical energy in the form of carbohydrates

To stabilize the environment in the Biosphere II habitat and enable it to become self-sufficient again, it would be helpful to

add plant producers to absorb excess carbon dioxide and produce oxygen.

In order to understand the carbon cycle, it is important to recognize where carbon can be found on earth. Carbon can be found in

air ocean water organic molecules plants animals bacteria

autotroph (plants, bacteria, algae)

an organism that can produce its own food

stomatal pores

are on the underside of the leaf and allow gases in and out. CO2 enters and is absorbed into surrounding cells

Carbon dioxide can be released into the atmosphere by all of the following EXCEPT: a) volcanic eruptions b) photosynthesis c) cellular respiration d) burning of fossil fuels

b) photosynthesis

The following organisms can incorporate nitrogen directly from the atmosphere into their bodies:

bacteria cyanobacteria

biomass

biomass consists of all the bodies of all the living things on the planet

each cell runs on chemical energy mainly found in

carbohydrate molecules(food)

carbon cycle: soil

carbon is held in the soil as organic matter which has not yet decomposed

Select all of the processes that cause flux of carbon into the atmosphere:

cellular respiration burning fossil fuels deforestation

Which molecule absorbs the energy of a photon in photosynthesis?

chlorophyll

What is the energy of a photon first used to do in photosynthesis?

energize an electron

The process whereby oxygen is depleted by the growth of microorganisms due to excess nutrients in aquatic systems is called ________.

eutrophication

The Calvin cycle reactions

fixation, reduction, and regeneration.

Based on your knowledge of how energy is released when carbon switches bonding partners, which molecule is a better energy source?

fructose

decomposers

fungi and bacteria

surface runoff occurs only

if the soil becomes saturated with water in a heavy rainfall.

heterotrophs (animals, humans)

incapable of photosynthesis that must obtain energy and carbon from food by consuming other animals

hydrosphere

is the area of Earth where water movement and storage occurs

biological carbon cycle

is the exchange of carbon between heterotrophs and autotrophs within and between ecosystems by way of atmospheric carbon dioxide

literfall

it includes the movement of any dead organic matter to the soil (leaves, people, animals)

carbonates

largest stores of carbon on the plant the hold 20 million billion tons

fossil fuels ( coal, oil, gas)

matter becomes trapped in rocks and it becomes a fossil fuel

Application of fertilizer results in plant growth because fertilizer provides the following critical nutrient(s):

nitrogen

photosynthesis releases

oxygen and produces carbohydrate molecules (sugars like glucose)

majority of carb molecules are produced by

photosynthesis

Select all of the processes that cause flux of carbon out of the atmosphere:

photosynthesis burning fossil fuels ocean absorption reforestation

carbon cycle: photosynthesis

plants absorb carbon dioxide gas from atmosphere and use energy from the sun to convert it into simple sugars

The majority of the water found on Earth is:

salt water

carbon in soil

soil contains more carbon than both biomass and atmosphere combined

Plants produce oxygen when they photosynthesize. Where does the oxygen come from?

splitting water molecules

Where in plant cells does the Calvin cycle take place?

stroma

photosynthesis requires

sunlight, carbon dioxde, water

the majority of nitrogen on earth is found in

the atmosphere

carbon fixation

the conversion of CO2 to an organic compound

respiration

the processes of generating energy from stored or eaten foods

biogeochemical cycle

the recycling of inorganic matter between living organisms and their nonliving environment

carbon cycle:respiration

the waste product of respiration is CO2 and this is released to the atmosphere as a gas. for example: humans breathing CO2 out

carbon cycle: ocean

there's a lot of C02 in the ocean because it dissolves easily. In the surface waters tiny free-floating plants (plankton) convert the dissolved carbon into simple sugars using sunlight to drive photosynthesis

carbon cycle: soil respiration

they break down organic matter to release energy and CO2 which is released to the atmosphere

carbon cycle: fossil fuels

whenever we burn a substance which contains carbon, we release CO2 in the atmosphere