bio 1500 final exam homework answers study guide

What is diffusion?

the spontaneous movement of molecules away from areas of highest density

Which three of the following are types of transport proteins?

-aquaporins -channel proteins -carrier proteins

Find out the approximate elevation of Mt. Everest in meters. (Note: it is higher than Camp VI, which is mentioned in one of the readings.) Enter a number.

8848

Most animals that are larger than a single cell have a body part that is adapted to serve as a specialized respiratory surface. Which of the following are characteristics of ALL animal respiratory surfaces?

-They have a large surface area. -They are wet or moist.

What are the two primary functions of all respiratory systems?

-To provide oxygen to the cells of the body -To remove carbon dioxide from the body

Which of the following are examples of carbohydrates? Choose 3 answers from the list below.

-glucose -cellulose -chitin

The highest rates of diffusion are associated with (choose all that are correct!!):

-high temperatures -large diffusion surface area -steep concentration gradient

Which of the following are examples of lipids

-olive oil -bees wax -bacon fat

Given what you know about the production of CO2, which of the following body parts is likely to have the highest PCO2? (not PO2)

active muscles

Does a decrease in pH make it 'easier' or 'harder' for Hb to release oxygen?

easier

In birds, which structures expand and contract during inhalation and exhalation?

the air sacs

Match the type of animal with the type of respiratory system:

- mammal: lung - insect: tracheal system - earthworm: skin - fish: gills

Match the following organic molecules with their building blocks

- proteins: amino acids - carbohydrates: simple sugars - nucleic acids: nucleotides - lipids: fatty acids

According to the article, the geese achieve this feat by:

acquiring oxygen very efficiently

As a result of the sigmoidal shape of the O2-Hb dissociation curve, there is steep drop in Hb saturation across a small range of intermediate values for PO2 (e.g. between 20 and 35 mm Hg in the textbook figures). What is an advantage of the steepness of the relationship between PO2 and Hb saturation in this range?

A small drop in PO2 in this range results in a big 'unloading' of oxygen from the hemoglobin

Which of the following could be the outcome of hydrolysis?

A starch is broken into simple sugar molecules

A change in the amino acid sequence of a protein can change the ability of the protein to function correctly. Why?

Changing the amino acid sequence may change the 3D shape of the protein.

Why don't insects need to transport O2 in their blood, like mammals do?

The tracheal system delivers O2 directly to every cell in the insect.

What is the result of dehydration synthesis?

Two molecules form a chemical bond with each other

As a result of the sigmoidal shape of the O2-Hb dissociation curve, there is very little change in Hb saturation across a range of PO2 values when PO2 is high (e.g. between 80 and 100 mm Hg in the text book figures). According to the reading, what is an advantage of the relatively flat shape of the curve here?

PO2 can fluctuate quite a bit in this range while still maintaining very high levels of O2 saturation in your hemoglobin

According to your reading, 'heat is a by-product of metabolic activity, and active tissues are typically warmer than less active ones.' Based on this information, of the following body parts, which is likely to be the warmest?

active muscles

alveoli

air sacs in the lungs where gas exchange occurs

The function of the parabronchi in birds is most similar to the function of which structure in the mammalian respiratory system?

alveoli

residual volume

amount of air left in the lungs after exhaling

vital capacity

amount of air moving in and out of the lungs when exercising vigorously

If Hb has a high affinity for O2, it means that:

it will pick up O2 easily, but won't release it easily

If Hb has a low affinity for O2, it means that:

it will release O2 easily, but won't pick it up easily

What is the proton gradient used for?

making ATP

What does the term 'carbon fixation' refer to?

making organic compounds

The air in the lungs has lower O2 partial pressure than the outside atmosphere, and higher O2 partial pressure than the blood.

true

The bar-headed geese migrate between India and Mongolia .

true

The partial pressure of O2 (PO2) is lower on Mt. Everest than it is at sea level. This is because O2 makes up a lower percentage of the air molecules at high altitudes, but the total number of air molecules there is the same as at sea level.

true

Whereas glycine increases the flexibility of the polypeptide, proline makes it more difficult for the polypeptide to fold.

true

Match the level of protein structure with its description.

- primary: sequence of amino acids - secondary: folding or twisting caused by interactions between nearby amino acids - tertiary: interactions between distant amino acids in polypeptide, generating a 3D shape - quaternary: interactions between separate polypeptide chains

Which of the following are the four categories of organic molecules? Note: the question asks for the 4 categories, not for specific examples of organic molecules, and not for the building blocks of organic molecules

-carbohydrates -lipids -proteins -nucleic acids

tidal volume

Amount of air that moves in and out of the lungs during a normal breath

According to the reading, when a person is at rest, the Hb only gives up 20-25% of its oxygen during one circuit through the body. This seems inefficient. According to the reading what is an advantage of holding on to so much of the oxygen?

It allows the Hb to quickly release a lot of O2 if there is a sudden increase in O2 demand

Which of the following is the same thing as a proton?

H+

What are insect spiracles?

Holes in the body wall of the insect, through which air enters the tracheal system

In the video, what behavior did the katydid perform to increase the efficiency of its respiration?

It pumped air in and out of its abdomen

What is a limitation of this mechanism by which gases move across the respiratory surface?

It's only efficient over small distances

What molecule does the electron end up in at the end of the two light reactions (i.e. After Photosystems II and I)?

NADPH

One area in a cell has a higher density of a certain type of molecule compared to a neighboring area. This situation describes:

a concentration gradient

Which of the following foods is likely to contain the most cellulose?

a serving of broccoli

According to Fig. 23.20, is an increase in PCO2 (not PO2) associated with an increase or decrease in pH?

decrease

match the name of the process with how it happens. (note: reactant = a substance that takes part in a chemical reaction)

dehydration synthesis: a water molecule is removed from the reactant(s) hydrolysis: a water molecule is added to the reactants

When a fat is described as 'saturated,' what is it saturated with?

hydrogen

How does facilitated transport differ from diffusion?

in facilitated transport, the substance passes through a pore, or tunnel, inside other molecules in the membrane

The characteristic of the 'death zone' that prevents people from remaining there for more than 48 hours is:

insufficient oxygen

If a molecule is described as 'organic,' then which of the following statements must be true?

it contains carbon

What happens to Hb as it enters these warmer parts of the body?

it's affinity for oxygen decreases

What happens to Hb as it returns to the (relatively cooler) lungs?

it's affinity for oxygen increases

Phospholipids are important components of which cellular structure?

membranes

gas exchange

movement of O2 from air into blood, and of CO2 from blood into air

ventilation

movement of air between the outside world and the gas exchange surface

What type of organisms are responsible for the production of most of the oxygen on Earth?

phytoplankton

O2 partial pressure

portion of total gas pressure exerted by O2 rather than by other gases in the mixture

When Hb releases O2 more easily (i.e. has a lower affinity for O2), this is represented in the O2 dissociation curve as a shift to the:

right

What does it mean if a channel is gated?

sometimes the channel allows molecules to pass through, and sometimes it doesn't

There are 20 common amino acids, which are divided into categories based upon:

the chemical properties of the R group

What is remarkable about the migration of the bar-headed geese?

the elevation at which they fly

Where is the gas-exchange surface in the bird respiratory system, i.e. where does oxygen enter the blood and carbon dioxide leave the blood?

the lungs

What is the advantage of unidirectional air flow (i.e. air that flows in a loop) over bidirectional air flow (i.e. air that flows in and then back out the same way)? In unidirectional flow,...

there is less mixing of fresh and 'used' air

During the light-independent reactions, the Calvin Cycle requires NADPH and ATP. Where does the cell get these molecules?

they are produced during the light reactions of photosynthesis

What is the difference (or relationship) between the terms diffusion and osmosis?

they both function in the same way, but osmosis refers specifically to the diffusion of water molecules

After molecules have moved around until there is no longer a concentration gradient, how do the molecules behave?

they continue moving, but their density remains relatively even throughout the space

What is the function of the air sacs in the bird respiratory system?

they store air for short periods, enabling fresh air to flow through the lungs during exhalation

What is the overall function of photosynthesis, i.e. why do cells perform this process?

to make carbohydrates like glucose

Another word for 'protein' is polypeptide and another name for the R group is the side chain .

true

Gases move from an area of high partial pressure to an area of low partial pressure .

true

In the parts of the body that need Hb to release its oxygen efficiently, the pH is lower , the temperature is higher , and the PCO2 is higher . In these parts of the body, the Hb-O2 dissociation curve is shifted to the right .

true

What molecule is the source of the electrons in the electron transport chain?

water

What molecule is the source of the oxygen that is released as a byproduct of photosynthesis?

water

What molecule is the source of the protons that are used to establish the proton gradient?

water

According to the article, roughly what percentage of people who climb Mt. Everest die there

10%

According to the article, how many mountains in the world have a 'death zone?'

14

The functions of the mammalian respiratory system are to supply (1) to the cells, which they need for performing the process of (2), and to rid the body of (3) that was produced by cells as a byproduct of (4).

1: oxygen 2: cellular respiration or etc 3: carbon dioxide 4: cellular respiration or citric acid cycle

What benefit do cells obtain by using facilitated transport instead of simple (=unfacilitated) diffusion to move material across a membrane?

Some molecules have positive and negative regions (i.e. polarity) that prevent them from moving easily through the membrane; facilitated transport overcomes this problem

Why do insects sometimes close their spiracles?

To conserve water

When Dr. Bush was a young child, she callously tried to kill a grasshopper by holding its head under water. It didn't work. Why not?

because although insects breathe air, they don't inhale it through their mouths

The product of the light-independent reactions is a molecule called G3P. What does the cell use it for?

building carbohydrates such as glucose

All animals have a respiratory surface that gases cross. What is the mechanism by which the gases move across the respiratory surface?

by diffusion