Biochemistry 2280A Chapter Notes - Chapter 1: Actin, Acetal, Aldehyde

47 views25 pages

periwinkleswan242

3 Jul 2016

School

Department

Course

Professor

For unlimited access to Textbook Notes, a Class+ subscription is required.

Document Summary

Chapter 1: cells the fundamental units of life. Cells vary widely in terms of size, shape and chemical requirements. Some cells require oxygen to live, others don"t; some cells require as little as air, sunlight and water as their raw materials while others need a complex mixture of molecules produced by other cells. Differences in cell size, shape and chemical requirements often reflect differences in cell function. Some cells are specialized factories for producing particular substances like hormones, while others are engines like muscle cells that burn fuel to do mechanical work. Living cells all have a similar basic chemistry. Living cells may differ in appearance but on the inside they are fundamentally similar in terms of their chemistry. This flow of information from dna to rna to protein is so fundamental to life that it is referred to as the central dogma.

Related Questions

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

Question1.1. Which of the followingenergy sources are considered renewable? (Points : 1)

Gasoline
Tidal energy
Coal
Nuclear energy

Question2.2. The most crops that canbe harvested from a plant population, while leaving the populationintact for future harvests, is known as____________. (Points :1)

cash crop
maximum sustainableyield
equilibrium theory
sustainabilityfactor

Question3.3. The system of____________ was started in 1903 by Roosevelt and is administeredby the U.S. Fish and Wildlife Service. (Points : 1)

habitat preserves
national parks
national wildliferefuges
resource managementoversight

Question4.4. Urban sprawl refersto___________. (Points : 1)

the height of skyscrapersin modern cities
the population growth incities
the spread of cities intonew areas
the sustainabledevelopment of a city