Biology 101

The "honeymoon period" of diabetes he refers to means:

A time when the pancreas is still producing some insulin sporadically.

Endocytosis

A vesicle inside the cell fuses with the plasma membrane and releases its contents outside the cell

Mitochondria appear in the greatest numbers in cells that are _____.

Metabolically Active

Which of these is a source of lactose?

Milk

How does Tim explain how the #showmeyourpump arose?

Miss Idaho came out in her swimsuit with her insulin pump proudly on the outside of her suit.

active transport

Requires energy from the cell. molecules move against their concentration gradient

After reading the paragraph below, answer the questions that follow. Much of the intracellular structure of a eukaryote cell is involved in protein synthesis. The accompanying figure shows the amounts of protein in cells at different parts of the cell cycle between two cell divisions. G1 is a stage just after the cell has divided, and G2 is the stage just before the cell divides again. S is a stage when the cell is synthesizing material such as DNA, mitochondria, and other organelles. The protein measured in the cells was likely synthesized by?

Ribosomes

You would expect a cell with an extensive Golgi apparatus to _____.

Secrete a lot of material

Which of the following is a function of the central vacuole?

Storing compounds produced by the cell

A mutation in the gene for hormone A causes it to be unable to bind to its receptor protein. What do you predict will likely happen?

The receptor protein will not be activated and therefore will not initiate a signal transduction pathway.

What do the rough endoplasmic reticulum, Golgi apparatus, and lysosomes have in common?

They are constructed of interrelated membranes.

The concentration of solutes in a red blood cell is about 2%. Sucrose cannot pass through the membrane, but water and urea can. Osmosis would cause red blood cells to shrink the most when immersed in which of the following solutions?

a hypertonic sucrose solution

The plant cell wall...

is a protective structure made of cellulose fibrils.

Which of the following structure(s) is/are found in prokaryotic cells?

ribosomes

The Golgi apparatus...

store, modifies and packages proteins

The primary structure of a protein is....

the amino acid sequence of the polypeptide chain.

A hydrogen bond is _____.

A weak interaction between two molecules

The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of?

Active Transport

Which of the following is an accurate comparison of active transport and facilitated diffusion?

Active transport moves solutes against their concentration gradient; facilitated diffusion moves substances down their concentration gradient.

Lactase deficiency is more common in Asian, Native American, Mediterranean and some African populations than it is among people with northern or western European ancestry. How would you explain why this is so?

Although most mammals, including humans, are not able to digest the milk sugar, lactose, after infancy, the ancestors of northern and western Europeans relied on dairy products as an important part of their food supply. When other food sources were in low supply, mutations that allowed the expression of the enzyme lactase to persist past childhood conveyed an advantage to adults who were able to include dairy products in their diet.

Which of the following hypothetical situations might result in a blood sugar level that is too high?

An individual's insulin receptors are defective. An individual has an autoimmune disorder that destroys the beta cells of the pancreas.

Your throat is dry, and you want the last cough drop in the box to last a long time in your mouth. What should you do?

Keep the cough drop whole. This maintains the smallest surface-to-volume ratio and slows the dissolution of the cough drop.

Which of the following statements regarding lactose tolerance is true?

Lactose tolerance has evolved independently in multiple different human populations.

Which plant cell organelle converts chemical fuel into packets of chemical energy that can power the cell?

Mitochondrion.

A group of single-cell organisms collected from the ocean was brought into the lab for examination. The lab assistant was concerned that the water had become full of toxic waste products and so added clean water to the culture. All of the organisms died, and when she looked at them under the microscope, all she could see were bits and pieces of them scattered throughout the water. What likely happened?

She added water that was hypotonic to the culture of organisms, and they ruptured.

3. The partial charges in this water molecule occur because of _____.

The unequal sharing of electrons between hydrogen and oxygen

A glucose molecule is to starch as __________.

a nucleotide is to a nucleic acid

A characteristic of every animal hormone is that the hormone _____.

acts as a regulatory message or signal between cells

The membranous compartmentalization of a cell

allows different chemical conditions to be maintained in different parts of the cell.

Mitochondria are found in _____.

both plant cels and animals cells

The fluid mosaic model describes the plasma membrane as consisting of?

diverse proteins embedded in a phospholipid bilayer.

The production of estrogen and progesterone decreases during menopause. This can cause thinning of bones and brief moments of feeling hot. What is another biological effect of low amounts of these hormones in women?

inability to reproduce successfully

The maximum size of a cell is limited by _____.

its need for enough surface area to make exchanges with its environment

Which of the following organelles breaks down worn-out organelles?

lysosomes

What carries instructions for making proteins from the nucleus into the cytoplasm?

mRNA

glucose + glucose —> _____ by _____.

maltose + water ... dehydration synthesis

You're on the pilot episode of a new game show called "The Transport Factor." The host hands you three different amino acids, four different sugars, and two different ions. Then the host shouts, "How many different proteins does the cell need to move these molecules across the plasma membrane using facilitated transport?" Quickly, you correctly respond: _____.

nine

A protein containing more than one polypeptide chain exhibits the ________ level of protein structure.

primary, secondary, tertiary, and quaternary structure

Overall, membranes seem to have a great deal in common, but on closer inspection it is revealed that membranes of different cells have unique properties. What is the primary component of membranes that gives membranes cell-specific properties?

proteins

Which option lists the sequence of events in the cell-signaling process in the correct order?

reception, signal transduction, response

Which of the following enables a cell to pick up and concentrate a specific kind of molecule?

receptor-mediated endocytosis

The skin is the body's largest organ. It's made up of many different types of cells. Oils, produced by the sebaceous glands, prevent the skin from drying and splitting. The pigment melanin, produced by melanocytes in the epidermis, protects the skin from the harmful effects of ultraviolet radiation. Sweat, released through ducts to the skin surface, helps to cool the body. The types of cells that produce these compounds have different numbers of specific organelles, depending on their function. Melanocytes use many enzymes to produce melanin. Based on their function, you would expect melanocytes in the skin to have a higher than usual number of

ribosomes.

Amino acids can be distinguished from one another by....

the chemical properties of their R groups.

What controls the net direction of molecules, such as oxygen, involved in passive transport?

the direction of the oxygen concentration gradient

Membrane proteins are synthesized by ribosomes that are attached to __________.

the endoplasmic reticulum

Which of the following characteristics of a protein will remain intact if the protein is denatured?

the number of amino acids in the protein

To enter or leave any cell, substances must pass through _____.

the plasma membrane

Tim was how old when he developed diabetes?

15

All proteins can be made from varying combinations of ___________amino acids.

20

Many names for sugars end in the suffix ____________.

-ose

Cells A and B are the same size and shape, but cell A is metabolically quiet and cell B is actively consuming oxygen. Oxygen will diffuse more quickly into cell _____ because _____.

... the diffusion gradient there is steeper

Diffusion

A form of passive transport. Molecules move across the plasma membrane by crossing the lipid bilayer

Facilitated Diffusion

A form of passive transport. Molecules move across the plasma membrane using a transport protein.

Glycogen is _____.

A polysaccharide found in animals

Which of the following statements about cellular metabolism is false?

Cellular metabolism occurs in animal but not plant cells.

Which of these is a polysaccharide?

Cellulose

_____ is the most abundant organic compound on Earth.

Cellulose

_____ are found only in plant cells, but _____ are found in both plant and animal cells.

Central vacuoles; ribosomes

The day he was diagnosed Tim:

Drank many cokes on a bus trip.

atrazine-exposed male frogs have decreased fertility over the control group

Estrogen level too low and Estrogen molecule is structurally defective

Which of these statements describes what occurs in facilitated diffusion?

Facilitated diffusion of solutes occurs through protein pores in the membrane.

Of the following sugar molecules, which is not a disaccharide?

Fructose

Which of the following is part of the endomembrane system?

Golgi apparatus

Which of the following statements about hormones and the endocrine system is true?

Hormones only affect specific cells having the appropriate receptors

The oil and vinegar in your salad dressing remain separate from one another due to the _____ properties of the oil.

Hydrophobic

How are ionic bonds formed?

In ionic bonds, one atom gives up an electron to a second atom.

How do glucagon and insulin differ?

Insulin causes some cells to take up glucose, whereas glucagon causes some cells to secrete glucose.

Tay-Sachs disease results from the malfunction of?

Lysosomes

The genetic center of the eukaryotic cell is the __________.

Nucleus

Where is the genetic information of the cell stored?

Nucleus

Which of the following statements about the cytoskeleton is false?

Once laid down, the elements of the cytoskeleton are fixed and remain permanently in place.

A hydrogen atom has one electron. How many covalent bonds can hydrogen form?

One

In a water molecule, hydrogen and oxygen are held together by a ________ bond.

Polar Covalent

The atoms in the molecule of water shown below are held together by which type of bond?

Polar covalent bond

Antidiuretic hormone (ADH) targets kidney cells and blood vessels, whereas growth hormone (GH) targets many different kinds of cells throughout the body. Which of the following is the best explanation for this observation?

The GH receptor is expressed in many different cells, whereas the receptor for ADH is expressed primarily in kidney select blood vessel cells.

Which of the following describes the function of the chloroplast?

The chloroplast converts light energy to chemical energy.

Which of the following statements regarding the endomembrane system is false?

The endomembrane system is a system of interrelated membranes that are all physically connected.

What is the relationship between the Golgi apparatus and the plasma membrane?

The finished products of the Golgi apparatus may leave the cell through vesicles that fuse with the plasma membrane.

Two proteins have the same number and type of amino acids. How is it that they can have different shapes and therefore different functions?

The order in which the amino acids are arranged differs between the two proteins.

Excoytosis

The plasma membrane forms a pocket that pinches inward forming a vesicle that contains areal fro outside the cell

Lactose is a disaccharide (two monosaccharides joined together). To metabolize lactose, individuals require an enzyme known as lactase. What is true about this reaction?

The reaction hydrolyzes the sugar.

2. Which of the following describes a covalent bond?

Two or more atoms share electron pairs.

A fatty acid containing at least one double bond is called _____.

Unsaturated

Aquaporins are proteins that facilitate the transport of __________ across the membrane.

Water

Controlled studies conducted by scientists at University of California-Berkeley and described in module 26.3 of your text have shown that __________.

atrazine-exposed male frogs have decreased fertility over the control group

How do fatty acids travel through a cell membrane?

carrier proteins

Tay-Sachs disease...

causes an accumulation of lipids in brain cells.

The nucleoid region of a prokaryotic cell

contains the cell's DNA.

The function of the chloroplast is to _____.

convert light energy to chemical energy

The structural framework in a cell is the

cytoskeleton

Where would ribosomes be located that are responsible for producing enzymes which play a role in sugar metabolism?

cytosol

The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of?

endocytosis

Which is one of the three major categories of sex hormones?

estrogens

A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of?

facilitated diffusion.

Compared to the endocrine system, the nervous system has a

faster response, but the signal does not last as long.

What condition might result from an excess of aquaporins?

fluid retention in pregnant women

The storage form of carbohydrates is ________ in animals and ________ in plants.

glycogen; starch

Androgens stimulate...

growth of facial hair in humans.

Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment

is hypotonic to the protozoan

Protein synthesis requires the use of mRNA, which....

is translated by the ribosomes into the amino acid sequences of proteins.

Peptide bonds....

link amino acids

In their mechanism of action, a difference between lipid-soluble and water-soluble hormones is that _____.

lipid-soluble hormones may enter the nucleus of the target cell, whereas water-soluble hormones do not

Cholesterol belongs to which class of molecules?

lipids

The cells of a person with adrenoleukodystrophy (ALD) swell with a buildup of fatty acids. In other words, fatty acids are not being broken down. Which organelle is most likely failing to function correctly?

lysosome

The protein actin is a component of a(n) __________.

microfilament

Which of the following cytoplasmic structures functions in the transport of vesicles from the endoplasmic reticulum to the Golgi apparatus?

microtubules

The internal skeleton of a cell is composed of _____.

microtubules, intermediate filaments, and microfilaments

Where in a cell is ATP made?

mitochondria

In active transport,

molecules move across the plasma membrane against their concentration gradient.

Chloroplasts are found in __________.

plant cells and some protists

What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell?

plasma membrane

One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by

ribosomes

Which characteristic promoted the utilization of lipids as the first cell membrane?

self-assembly into a simple membrane

Where are lipids made in the cell?

smooth endoplasmic reticulum (ER)

The lipids in a cell membrane are arranged _____.

so that the nonpolar parts of two lipids point toward each other

A diet high in animal products and hydrogenated vegetable margarine may increase the risk for heart disease. This is because most animal fats are saturated and many hydrogenated vegetable margarines contain high levels of trans fats. Which meal is high in fiber, low in saturated fats, and high in unsaturated fats?

spaghetti noodles with olive oil and broccoli

When you eat a plant, you derive energy from the stored __________, but not from the __________ component.

starch ... cellulose

The plasma membrane would fit into which general function category?

support, movement, and communication

Which of the following is a function of the rough endoplasmic reticulum?

synthesizing receptor proteins

Because water-soluble hormones are unable to pass through the plasma membrane, the cellular action they initiate results from _____.

the activation of a signal transduction pathway by binding to a membrane receptor

Plasma membranes are selectively permeable. This means that

the plasma membrane allows some substances to enter or leave a cell more easily than others.

Proteins differ from one another because....

the sequence of amino acids in the polypeptide chain differs from protein to protein.

Water crosses the plasma membrane

through facilitated diffusion or diffusion.

The function of the nucleolus is?

to manufacture ribosomal RNA.

As cell size increases, the....

volume increases proportionally more than the surface area.

Which of the following clues would tell you whether a cell is prokaryotic or eukaryotic?

whether or not the cell is partitioned into compartments by internal membranes