HNRS 1007 Lecture 4: Energy and Respiration.docx

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violetmink144

17 Oct 2014

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Enzymes: a catalyst is a chemical agent that speeds up a reaction without being consumed by the reaction, an enzyme is a catalytic protein. How enzymes lower the ea barrier: enzymes catalyze reactions by lowering the ea barrier, enzymes do not affect the change in free energy ( g); instead, they speed up reactions that would occur eventually. General environmental factors, such as temperature and ph. Enzyme evolution: altered amino acids in enzymes may alter their substrate specificity, under new environmental conditions a novel form of an enzyme might be favored. Cofactors: cofactors are nonprotein enzyme helpers, cofactors may be inorganic (such as a metal in ionic form) or organic, an organic cofactor is called an coenzyme, coenzymes include vitamins. Enzyme inhibitors: competitive inhibitors, bind to the active site, compete with the substrate, noncompetitive inhibitors, bind away from the active side, decrease activity, examples of inhibitors include, toxins, poisons, pesticides, antibiotics, and many drugs.

Related Questions

As entropy increases there will be more useful energy to doâworkâ. True or false?

False. As entropy increases, there will generally be less usefulenergy to do work. We can think of entropy as usually being presentin the form of heat energy. Imagine a car motor, which attempts toturn chemical potential energy into kinetic energy (movement). Lessefficient motors will get hotter for the same amount of fuelconsumed. When you drive a car you hope that most of the fuelenergy is converted into kinetic energy and not lost as heat(entropy). The hotter the car (and thus the more entropy) the lessefficient the ability to do âworkâ (the moving of the vehicle).

True. As entropy increases, there will generally be more usefulenergy to do work. We can think of entropy as usually being presentin the form of heat energy. In most biological and mechanicalsystems it is heat energy which is captured to do useful 'work'.Heat energy, the random movement of molecules, and increases inentropy are central to doing useful work.

Biological systems sometimes appear on the surface to break theSecond Law of Thermodynamics â by seemingly increasing the order inthe overall system. They donât. Why?

a. Earth (and living things on it) are not a closed system. Thesun's constant input of energy in the form of photons is harnessedby living things to create internal order within themselves. Butwithout such a constant input of energy, most biological systems onearth would break down.

b. The Second Law tells us that no natural process can occurunless it is also associated with an increase in the entropy of theuniverse. A living organism (such as an animal or plant) brings inmatter and energy from its environment and uses this to creategreater order within its body: the processes of life. But it isimportant to keep in mind that all animals and plants are also partof a larger system of the environment around them. While creating asmall âpocketâ of order, the processes of life (metabolism,movement, etc..) releases heat into the environment â thusincreasing the entropy of the universe and following the2^nd law.

c. Living things, by harnessing energy to create order (withinand around themselves) actually create a paradox in questionssurrounding the first and second laws of thermodynamics andseemingly violate many previously held assumptions.

d. Both a and b above are correct.

When plants capture energy in the photons of sunlight andconvert that energy into the chemical bonds of organic molecules,are they creating new energy?

No, the energy is being transferred from one form into another.But no new energy is being created.

No, the overall total energy is decreasing over time.

Yes, by capturing photons, the plants are creating newenergy.

Yes, by capturing photons, the plants are creating new energy -of a different wavelength.

ceruleanhamster867

Question 1

Which is a population?

		All the members of a species inhabiting a given location.
		All the interacting populations in a given area.
		The living community and the physical environment functioning together as an independant and relatively stable system.
		All of the above

5 points

Question 2

Which is not an abiotic factor?

		Intensity of light
		type of substratum
		range of temperatures
		living things

5 points

Question 3

What does the fertility rate have to be in order to keep a population stable (neither increasing or decreasing)?

		1
		2
		3
		4

5 points

Question 4

Japan's population is falling due to a low fertility rate.

True

False

5 points

Question 5

When the population remains relatively constant over a number of years this is known as

		steady state
		abiotic state
		biotic state
		Both abiotic and biotic states

5 points

Question 6

Which are the living components of the environment?

		biotic factors
		abiotic factors
		neutrality factors
		non-organic factors

5 points

Question 7

What is carrying capacity?

		The maximum number of organisms the resources of an area can support.
		The amount of abiotic factors in an area.
		The amount of energy.
		The density of a star.

5 points

Question 8

Which can synthesize their own food?

		heterotroph
		herbivore
		autotroph
		carnivore

5 points

Question 9

Which is an example of a saprophyte?

		vulture
		bacteria
		mouse
		frog

5 points

Question 10

This consumes both plants and animals.

		Carnivore
		Herbivore
		Omnivore
		Tachivore

5 points

Question 11

Global warming might actually cause global freezing.

True

False

5 points

Question 12

There are good odds that a future virus can cause the extinction of the human race.

True

False

5 points

Question 13

A heterotroph can make its own food.

True

False

5 points

Question 14

According to the 1st Law of Thermodynamics, disorder always increases.

True

False

5 points

Question 15

In 5 billion years the Sun will expand and burn up the Earth.

True

False

5 points

Question 16

Einstein stated that World War 4 will be fought with sticks and stones.

True

False

5 points

Question 17

Which is not true of the First Law of Thermodynamics?

		Energy cannot be created
		Energy cannot be destroyed.
		Energy can change forms.
		All are true.

5 points

Question 18

According to the Second Law of Thermodynamics, the heat death of the universe is its ultimate fate.

True

False

5 points

Question 19

Which is organic?

		CH₄
		CO₂
		H₂O
		N₂

5 points

Question 20

The Sun and the core are the primary energy sources for the Earth.

True

False

limejackal967

Select the statements that correctly represent the theory ofevolution. Select all that apply.

Evolution is partly about inheritance. Evidence of evolution isseen in structures such as wisdom teeth and the tail bone inhumans. These structures are thought to be âleft overâ from ourancestors and no longer appear to have any essential function inmodern humans.

Natural selection means that todayâs organisms are perfectlyadapted after millions of years of fine-tuning. No further changesare necessary because of all the progress that has been made bynatural selection.

We can see evidence of past natural selection in adaptationssuch as the camouflage of moths perched on the bark of their hosttree. We can also see natural selection at work today if we trackhow populations change in rapidly changing environments.

The theory of evolution does not apply to life today. It isstrictly about the history of life: what happened in the past asseen in fossils.

Scientists disagree about the main ideas of evolutionary theorybecause of incomplete or conflicting evidence.

Question 2

Select one answer.

10 points

The ability or tendency of organisms and cells to maintainstable internal conditions is called

metabolism

homeostasis

emergent property

evolution

Question 3

Select one answer.

10 points

Why do organisms maintain fairly steady conditions within theircells and bodies?

They need to keep conditions stable so that they can obtainfood.

Organisms just change along with whatever is happening in theoutside world, which is usually quite steady.

They must maintain stable conditions to keep their enzymesworking and generally to enable the chemical reactions of life.

Unstable conditions will destroy the DNA in cells; this is themost important risk for a cell facing physical or chemicalstress.

Question 4

Select one answer.

10 points

An organism or cell exhibits ____________ when it maintainssteady internal conditions despite changes in the outerenvironment.

homeostasis

evolution

balance

natural selection

Question 5

Select one answer.

10 points

Which type of molecule best illustrates the very strongrelationship between structure and function in biology?

enzymes

oxygen gas

all kinds of organic matter

water

Question 6

Select one answer.

10 points

Which best expresses how nutrients and energy move throughlife?

Nutrients flow from sunlight to organic matter to heat. Energycycles among all life forms.

Nutrients cycle among all life forms. Energy flows from sunlightto chemical energy to heat.

Nutrients and energy both are continually recycled in a greatcircle of life.

Question 7

Select one answer.

10 points

Which of the following is not a recurring theme in biology?

Living organisms maintain homeostasis.

Energy flows through living systems while matter isrecycled.

Evolutionary processes explain both the unity and adaptivediversity of life.

All of these are recurring themes.

Question 8

Select one answer.

10 points

Which statement about evolution is FALSE?

According to evolutionary theory, you are related to abacterium, to a yeast cell, to a snake, and to a whale. In fact,you are related to every species now alive on Earth, and to fossilspecies like dinosaurs as well.

Evolution occurs constantly, without end; there is no endpointin evolution.

Natural selection acts on genetic differences within apopulation to cause evolution. Individuals do not evolve.

Natural selection is about slow but steady progress. Through it,populations constantly get better-adapted. When this process iscompleted for all populations, evolution will come to a stop.

Question 9

Select one answer.

10 points

Imagine you have a peanut butter sandwich in front of you. Thesandwich is an example of _______.

matter

energy

Question 10

Select one answer.

10 points

You provide your gut bacteria with a warm place to live. Theyprovide you with vitamins and other services. This most directlyrepresents an example of...

shared ancestry of all life

natural selection

homeostasis

interdependence of life

HNRS 1007 Lecture 4: Energy and Respiration.docx

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