biology concept questions ch.4-5

In which of the following ways do lysosomes work within animal cells?

Lysosomes fuse with food vacuoles, digest food, and release nutrients into the cytosol.

elective permeability of the cell membrane results in what?

Only certain substances can enter or leave the cell.

Lysosomal storage diseases are rare in the general population. Why?

Such diseases are usually fatal in early childhood.

The genes for actin are said to be highly conserved. What does this mean?

The actin gene is similar across many species

Why are a cell's high-energy complex molecules (DNA, proteins, carbohydrates, lipids) so stable?

The activation energy required to break them down spontaneously is too high.

Imagine a metabolic pathway where Product D, a hormone, is the result of three chemical reactions: Molecule A →Molecule B →Molecule C →Product D. Enzymes A, B, and C, respectively, catalyze the three reactions. The pathway is controlled by feedback inhibition of Product D on Enzyme A. What will happen if very high concentrations of Product D are produced?

The concentrations of Molecule B will fall.

Two glucose solutions, A and B, are separated by a membrane that is permeable to water but impermeable to glucose. The glucose concentration in Solution A is much lower than in Solution B. Over time, what occurs?

The concentrations of glucose in both solutions will become more equal.

what is the best description of energy coupling in living things?

The energy released from exergonic reactions is used to drive endergonic reactions.

What must be true before a small, nonpolar substance can diffuse across a membrane?

The membrane must be permeable to the substance.

Pancreatic cells produce large amounts of enzymes for export into the digestive system. By contrast, muscle cells do NOT export digestive enzymes. How do you think that the number of ribosomes compares in the two cell types?

The pancreatic cell has many more ribosomes than the muscle cell.

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

They are constructed of a similar type of membrane

What happens to people with defective aquaporins?

They cannot reabsorb water, and they urinate very often

What is the common property of competitive and noncompetitive enzyme inhibitors?

They make it impossible for the substrate to bind to the active site.

Men with primary ciliary dyskinesia (PCD) have recurrent respiratory tract infections and immotile sperm. What is the cause of these symptoms?

a lack of dynein proteins

A transport vesicle within a cell can contain which of the following?

a newly made glycoprotein, as well as the glycoprotein with its attached phosphate groups

Imagine that you fill a basketball with as many ping pong balls as possible. The volume of the basketball is __________ the total volumes of all the ping pong balls. The surface area of the basketball is __________ than the total surface areas of all the ping pong balls.

approximately equal to; less than

A transport protein that provides a passageway across a membrane is a (an) __________. A transport protein that binds, then releases, its passenger is a (an) __________.

channel; carrier

Receptor-mediated endocytosis relies on which of the following?

coated pits (indentations)

The most abundant glycoprotein in the extracellular matrix (ECM) is __________. This protein attaches to __________, which are proteins in the plasma membrane that connect the ECM with the inside of the cell.

collagen; integrins

What feature of the mitochondrion enhances cellular respiration?

cristae,

What is the function of junction proteins?

form channels between adjacent cells

When you water a plant, you are giving it a(an) __________ solution. What effect does this have on the plant?

hypotonic; It remains standing upright.

The match between an enzyme and its substrate is called __________. This allows the reactions of __________ to occur.

induced fit; catalysis

Light and thermal energy are types of __________ energy. __________ energy is the potential energy that may be released in a chemical reaction.

kinetic; chemical

What changes would you expect to see in the liver cells of someone suffering from chronic alcoholism?

large amounts of endoplasmic reticulum; elevated levels of detoxifying enzymes

A white blood cell is 12-15 µm (microns) in diameter. If you wished to count the white blood cells in a blood sample, which type of microscope would you choose?

light microscope (these are big enough to be seen)

Which of the following organelles is found only in animal cells and NOT in most plant cells: cytoskeleton, lysosome, mitochondrion, chloroplast

lysosome

what does active transport allow a cell to do, that diffusion does not allow?

maintain different internal and external concentrations of substances

Which of the following is characteristic of prokaryotic cells but NOT eukaryotic cells? plasma membrane, nucleoid, production of proteins, flagella

nucleoid

In the most general sense, which of the following is the correct description of cellular respiration?

oxygen is used, carbon dioxide is released, ATP is created

What would happen if a careless health-care worker gave a patient a hypertonic intravenous solution?

patient cells will shrink

You have identified a new organism. It has ribosomes, chromosomes, a cell wall, and plasmodesmata. This new organism is most likely a(n) __________.

plant!

Which tissue type would you expect to contain a large proportion of anchoring junctions?

skin

The plasma membrane fits into which of the four general function categories defined in your test?

support, movement, and communication

After their synthesis, proteins are modified and sorted by ___(what)__ located in the cell's _(where)___. An example of such a modification is __________.

the Golgi apparatus; cytoplasm; adding a phosphate group

Which of the following developments might have contributed to mitochondria becoming endosymbionts in eukaryotic cells?

the increasing availability of atmospheric oxygen

What determines the direction of diffusion of a small, nonpolar molecule, such as oxygen, across a membrane?

the oxygen concentration gradient

In plants, chlorophyll molecules are located within sacs called __________, which in turn are suspended in the __________ of the __________.

thylakoid; stroma; chloroplast

When you hear the terms: contractile, digestive, storage, pigment and poisonous, which of the following organelles comes to mind?

vacuole