Bio Ch. 1-4 LAUNCHPAD quizzes

whole wheat bagels

A carbohydrate-loading athlete would most likely consume _____.

oil

A doctor in Ethiopia is prescribing ready-to-use-therapeutic food (RUTF) peanut butter to malnourished children. Which of these would you expect to be ingredients in this RUTF peanut butter?

Gram-negative bacteria

A doctor is able to isolate and grow a bacterium that is causing an infection in one of his patients. He prescribes penicillin, and when his patient returns one week later, the patient demonstrates no signs of improvement. This infection is likely caused by _____.

that is required in large amounts

A macronutrient is a nutrient _______.

more than 9

A mother is nursing her infant. Of the 20 amino acids that exist, 9 would be considered essential for the mother. How many amino acids would be considered essential for her infant?

micronutrient

A multivitamin supplement is a(n) _____ supplement.

No, I will not write you a prescription for penicillin because it will not be effective against a viral infection.

A patient has a rhinovirus infection, causing her to suffer with a cold. She goes to her doctor to ask for a prescription for penicillin. What should the doctor say?

swelling of the extremities

A pediatrician is examining a child who she has diagnosed with malnutrition. What symptoms will the child likely demonstrate?

vitamins Y and Z

A researcher is culturing mouse cells in the laboratory. When he treats cells with four vitamins―W, X, Y, and Z―these cells survive and grow; he knows that some of these vitamins are essential nutrients. However, when he treats cells by removing one vitamin at a time, he gets the following results: vitamin W, cells live; vitamin X, cells live; vitamin Y, cells die; vitamin Z, cells die. Based on these results, which of the vitamins are likely essential nutrients?

amino acids that can't be synthesized (directly) by mouse cells

A researcher is trying to culture mouse embryonic stem cells, and is providing them with glucose (sugar) as a food source. In order for these cells to survive in culture, he must also add a mixture of essential amino acids to the culture medium. These essential amino acids are _____.

Ribosomes in the mitochondria

A woman has taken antibiotics, and is experiencing severe side effects in the form of nausea and lethargy. This could be due to the fact that the antibiotics are targeting ribosomes _____.

anabolic; catabolic

A(n) _____ reaction creates bonds between substrate units; a(n) _____ reaction breaks down bonds between substrate units.

pre-existing cell

According to the cell theory, all cells come from a _____.

streptomycin

According to the text, which antibiotic(s) can pass easily through the Gram-negative bacterial cell wall and interfere with protein synthesis?

Human cells have ribosomes that do not bind streptomycin; only prokaryotic ribosomes are affected by this drug.

Although both humans and bacteria have ribosomes, streptomycin—which blocks ribosome function—does not harm a human who ingests it. Why?

It is not possible to consume excess amounts of vitamin C.

Consuming excess amounts of the water-soluble vitamin C can lead to _____.

False

Corn lacks the essential amino acids isoleucine and lysine. Beans lack the essential amino acids tryptophan and methionine. Soy contains all the essential amino acids. Based on this information, is the following statement true or false? You can survive on a diet with corn-based proteins alone.

all the essential amino acids

Corn lacks the essential amino acids isoleucine and lysine. Beans lack the essential amino acids tryptophan and methionine. Soy contains all the essential amino acids. Use this information to complete the following statement: Many traditional diets combine corn (e.g., tortillas) with beans to provide _____,

Yes, because the active site binds specifically to the substrate to carry out the reaction.

Do you think that a mutation in an enzyme that changes its active site would change the function of the enzyme?

proposed prokaryotic orgin of of certain eukaryotic organelles

Endosymbiosis refers to the _____.

decreasing the activation energy.

Enzymes speed up chemical reactions by _____.

Fungi are eukaryotes, like humans, thus their cellular components are similar.

Fungi are eukaryotic organisms. Scientists have found it more challenging to develop treatments for fungal infections (e.g., yeast infections, athlete's foot, and certain nail infections) than for bacterial infections. Why is this so?

a dye is trapped within the cells during the Gram staining procedure

Gram-positive and Gram-negative bacteria are most commonly differentiated in the laboratory by whether__________.

-Eukaryotic cells have organelles, whereas prokaryotic cells do not -Prokaryotic cells are generally smaller than eukaryotic cells.

How are eukaryotic cells different from prokaryotic cells? Select the TWO answers that are correct.

-RNA is single-stranded, whereas DNA is double-stranded. -Uracil is used in RNA, whereas thymine is used in DNA.

How do RNA and DNA molecules differ? Select the TWO answers that are correct.

These antibiotics disrupt the formation of the cell wall so it cannot counteract osmotic pressure in a hypotonic environment, resulting in cell lysis.

How do penicillin and similar antibiotics affect prokaryotic cells?

These antibiotics interfere with protein synthesis.

How do streptomycin and similar antibiotics affect prokaryotic cells?

-Phospholipids have two fatty acid tails, whereas triglycerides have three. -Phospholipids have a hydrophilic phosphate group in place of one fatty acid tail.

How do triglycerides and phospholipids differ? Select the TWO answers that are correct.

It reduces the energy of activation, which makes the reaction it facilitates more likely to occur and speeds up the production of the chemical product.

How does an enzyme affect the activation energy of a reaction?

Prokaryotic DNA is contained in the cytoplasm, whereas eukaryotic DNA is contained in the nucleus.

How does the DNA of prokaryotic cells differ from the DNA of eukaryotic cells?

Because cells swell in a hypotonic environment, the bacterial cell wall counteracts the outward osmotic pressure and prevents the cell from bursting.

How does the cell wall protect prokaryotic cells in a hypotonic solution?

The oxygen has a partial negative charge and the hydrogens have a partial positive charge, yielding a weakly polar water molecule that can form hydrogen bonds.

How does the molecular structure of a water molecule affect its polarity?

-When an enzyme binds a substrate, the enzyme's shape changes to facilitate a chemical reaction. -Enzyme shape determines what substrate the active site can bind.

How does the shape of an enzyme affect its function? Select the TWO answers that are correct.

Water is a polar molecule that disrupts ionic bonds between sodium and chloride.

How does water dissolve table salt?

The mold is secreting a substance that is slowing down the growth of nearby bacteria, but not causing them to burst.

How would you interpret a petri dish with a single bacterial species that has small bacterial colonies growing near some contaminating mold and large bacterial colonies far away from the mold?

simple diffusion

If a solute is moving through a phospholipid bilayer from an area of higher concentration to an area of lower concentration without the assistance of a protein, the manner of transport must be _______.

The conversion of substrate to products would decrease and the enzyme would no longer be able to bind to its substrate efficiently

If the shape of an enzyme's active site were to change, what would happen to the reaction that the enzyme usually conducts?

molecules move from an area of low to high concentration

In active transport _____.

is broken into its products

In the process of catabolism, a substrate _____.

amino acids; monosaccharides

In the process of digestion, proteins are broken down into _____, whereas carbohydrates are broken down into _____.

ribosomes, rough ER, and Golgi apparatus

Insulin is a protein hormone secreted by certain pancreatic cells into the bloodstream. Which of the following organelles are involved in the synthesis and secretion of insulin?

High salt is hypertonic and causes the bacteria to shrink because water leaves the bacterial cell

Many foods—for example, bacon and salt cod—are preserved with high concentrations of salt. How can high concentrations of salt inhibit the growth of bacteria?

Grow the mold in a large vat, purify chemicals from the vat, and see if any of the chemicals can interfere with the growth of bacteria on the petri plate.

Many kinds of molds produce antibiotics that can slow down the growth of bacteria. If you were looking for a new antibiotic produced by a particular mold, how might you do this properly?

essential

Nutrients that can't be made by the body are called _____.

monosaccharides; small intestine

Once starch in your diet has been broken down into _____, those subunits are absorbed in the _____.

the enzyme and change its shape, so that it can bind to a substrate

One way a vitamin can act as a coenzyme is to bind to _____.

water; higher

Osmosis is the movement of _____ into solutions with _____ concentrations of solutes.

essential micronutrient

Our bodies cannot synthesize vitamin C, but they require it in small amounts. Therefore, vitamin C is a(n) _____.

cell wall synthesis; swelling and rupturing of the cell

Penicillin interferes with __________________, causing bacteria to die from ______________.

mold

Penicillin is isolated from _____.

Ice would sink rather than float, so there would be no ice sheets or ice bergs.

Polar bears rely on Arctic ice sheets and icebergs on the surface of water as a part of their habitat. How would the habitat of polar bears be affected if solid water was more dense than liquid water?

Mitochondria are the most metabolically active and require the most energy.

Some inherited syndromes, for example MERRF (myoclonic epilepsy with ragged red fibers), interfere with the function of mitochondria. From what you know about mitochondria, why do you think the muscles and the nervous system are the predominant tissues affected in MERRF?

active transport

Sugars are large, hydrophilic molecules that are important energy sources for cells. Sugars can enter cells from an environment with a very high concentration of sugar by

catabolic

Termites have enzymes that are capable of breaking down cellulose to its component sugars, which is something that humans cannot do. What type of metabolic pathway is described for the termites?

how eukaryotic cells might have evolved mitochondria and chloroplasts within their cells

The "endosymbiotic hypothesis" is a concept that explains _____.

grow, develop, and repair itself.

The body needs nutrients to:

The building blocks that form living organisms

The cell theory refers to ideas about _____.

are made up of cells

The cell theory states that living organisms _____.

protiens and fats

The macronutrients include _____.

Osmosis

The movement of water across a semipermeable membrane is _____.

serves as a mechanical barrier to hold the contents of the cell and selectively controls movement of molecules between the outside fluid and inside fluid of the cell

The plasma membrane _____.

what the enzyme acts on

The substrate of an enzyme is _____.

phospholipids; proteins

The two major components of cell membranes are _______ and _______.

fats

To repair a cell membrane, which macronutrient would supply the needed building blocks?

pink

Under a microscope, Gram-negative bacteria (when dyed with the Gram stain) appear _____.

Solution A must have a lower solute concentration than Solution B.

Water is moving across a membrane from solution A into solution B. What can be inferred?

-carbon backbone -carbon-hydrogen bond

What characteristics make a particular molecule organic? Select the TWO answers that are correct.

-total number of electrons in orbitals -number of protons and number of neutrons in the nucleus

What determines the identity of a particular atom? Select the TWO answers that are correct.

All living things are made of cells and those cells come from existing cells.

What does the cell theory state?

-transport wastes out of the cell that cannot otherwise cross the cell membrane -transport nutrients into the cell that cannot otherwise cross the phospholipid bilayer

What functions do membrane proteins serve?

Water diffuses out of the cells and they shrink.

What happens to plant cells placed in a high salt (10%) solution?

Calcium and Vitamin D

What ingredients in RUTF peanut paste specifically help bone growth?

the energy necessary to initiate a chemical reaction

What is activation energy?

Acids contain relatively few hydroxide ions, whereas bases contain excess hydroxide ions.

What is the relationship between acids, bases, and hydroxide ions?

Weight-bearing exercise causes the body to deposit calcium and phosphorus in bone.

What is the result of weight-bearing exercise on bone mass?

Hydrogen bonds between water molecules expand when solid.

What makes ice less dense than liquid water?

They must be digested into their constituent subunits.

What must happen to macromolecules before they can be absorbed by the body?

Far fewer bacterial colonies were growing near the mold on the plate.

What observation made Fleming investigate the mold on the plate?

amino acids

What subunits are proteins broken down into during digestion?

Their blood sugar will drop dangerously.

What will happen to someone who has low blood sugar and takes insulin?

membrane transport proteins are required in order for neurons to fire

When neurons "fire," the first thing that happens is that sodium ions enter the cell. This does not require an input of energy. One can infer from this that _____.

from protein in our diet

Where (or how) do we obtain essential amino acids?

Protons and neutrons are located in the nucleus, and electrons are located in orbitals.

Where are the protons, neutrons, and electrons located in an atom?

peanut butter

Which component of the peanut butter ready-to-use-therapeutic food (RUTF) that Dr. Manary uses provides essential amino acids?

Prokaryotic and eukaryotic cells both contain ribosomes to effectively use their genetic information.

Which of the following accurately compares prokaryotic and eukaryotic cells?

The hydrophobic core of a membrane will only allow hydrophobic (i.e., non-polar) substances to cross without a membrane protein

Which of the following accurately describes why specific material uses a protein to cross the membrane?

phospholipids

Which of the following cellular components would not be a good target for an antibiotic?

lysosome: internal support; cell and organelle movement

Which of the following combinations INCORRECTLY matches an organelle with its function?

macrotubules

Which of the following is NOT a cytoskeletal fiber in eukaryotic cells?

Nucleus

Which of the following is associated with eukaryotic cells but not with prokaryotic cells?

Mitchondria

Which of the following is not found in prokaryotic cells?

They are made of cells.

Which of the following statements best explains why bacteria are considered living organisms?

simple diffusion and facilitated diffusion

Which of the following types of transport are most closely related in terms of the energy requirements for moving material across a membrane?

cell membrane, ribosomes, and DNA

Which of these cellular components is(are) associated with all cells?

lean meat, such as chicken breast

Which of these foods is a rich source of protein?

fluid buildup in the legs and feet

Which of these is a sign of malnutrition?

Prokaryotes are smaller and lack the internal compartments that eukaryotes have.

Which of these statements is TRUE about prokaryotes and eukaryotes?

lysosome

Which organelle would cause the most damage to cytoskeletal fibers in the cytoplasm if its contents were to leak into the cytoplasm?

electrons in the outermost energy shell

Which part of an atom forms covalent bonds with other atoms?

dissolved sodium ions

Which solute is least likely to cross a membrane by simple diffusion?

It is not always associated with starvation.

Which statement applies to malnutrition?

A weak bond between the slightly negative oxygen atom of one water molecule and the slightly positive hydrogen atoms of another water molecule

Which statement describes a hydrogen bond between two water molecules?

They are usually cofactors required for proper enzyme function.

Which statement is true of micronutrients?

Human cells must derive "pre-assembled" essential amino acids from food.

Which statement is true regarding essential amino acids?

Cofactors and coenzymes can replace enzymes in cells.

Which statement regarding cofactors and coenzymes is false?

-Anabolic reactions add chemical bonds and result in smaller molecules being built up into larger ones. -Catabolic reactions remove chemical bonds and result in larger substances being broken down into smaller ones.

Which statements describe catabolic and anabolic reactions? Select the TWO answers that are correct.

-Cofactors and coenzymes both facilitate the binding of enzymes to substrates. -Cofactors can be organic or inorganic molecules, whereas coenzymes are only organic.

Which statements describe cofactors and coenzymes? Select the TWO answers that are correct.

-The hydrophilic head interacts with the external environment or the cytoplasm, and the hydrophobic tail interacts with other phospholipid tails within the cell membrane. -The cell membrane is composed of a bilayer of phospholipids, each of which contains a hydrophilic head and a hydrophobic tail.

Which statements describe the structure of the cell membrane? Select the TWO answers that are correct.

-baking soda -drain cleaner

Which substances have an alkaline pH? Select the TWO answers that are correct.

-keep plant upright -maintain cell shape

Which tasks do water vacuoles and cell walls both perform in plant cells? Select the TWO answers that are correct.

Animals do not have chloroplasts and must depend on organisms that can photosynthesize the energy they need.

Why are chloroplasts essential to the survival of many animals as well as plants?

Eukaryotic protein synthesis is not disrupted because these antibiotics do not disrupt eukaryotic ribosomal activity.

Why are eukaryotic cells unaffected by streptomycin and similar antibiotics?

They can be assembled into large molecules, but organisms need only small quantities of them in the diet.

Why are nucleic acids considered macromolecules but not macronutrients?

In the absence of water, sodium and chloride form ionic bonds and aggregate into crystals.

Why do salt crystals form in a pan of seawater from which the water has been evaporated?

The presence of a cofactor allows some enzymes to bind to their substrates.

Why do some enzymes need a cofactor in order to function?

The bilayer is a barrier to some, but not all, substances on either side of it.

Why is the phospholipid bilayer considered semipermeable?

-It separates the cellular environment from the external environment. -It acts as a barrier for some, but not all, molecules on either side of it.

Why is the phospholipid bilayer important to cell survival? Select the TWO answers that are correct.

Our bodies cannot manufacture them.

Why must essential amino acids be consumed in our diet?

both oil and peanut butter

Workers are preparing RUTF peanut butter, and are mixing oil, sugar, peanut butter, and milk powder together. Which ingredient in this RUTF peanut butter would provide children with fat, but not all of the essential amino acids?

oxygen from the side with the higher concentration to the side with the lower concentration

You create an artificial membrane that contains phospholipids but not proteins. Which substance will be able to cross that membrane and in which direction?

The cell wall is made of peptidoglycan.

You find a single-cell organism with a cell wall in the soil of a forest—can this organism be an animal? Which of the following characteristics would indicate that the organism is a bacterium and not a plant?

Because enzymes are specific, the plant enzyme's active site would not bind to glycogen as a substrate.

You have identified an enzyme that breaks down a storage form of sugar in plants (starch) into simple sugars. How would this enzyme react with a storage form of sugar (glycogen) in humans

by mixing the enzyme with cellulose and measuring the appearance of glucose in the tube

You have isolated an enzyme with unknown specificity. If it is a cellulose digesting enzyme, one can verify that by mixing the enzyme with _____.

You will be able to digest table sugar but not rice.

Your doctor tells you that you have a mutation in the enzyme that breaks down complex carbohydrates. That enzyme does not work anymore. What might be the result?