Physio Chapter 3

Identify the features common to all cells. Choose all the apply

• cell membrane

• cytoplasm

• ribosomes

• nucleus

• cell wall

• DNA
  
  

cell membrane, cytoplasm, ribosomes, DNA

What is the name of all the cell contents between the nucleus and the cell membrane?

cytoplasm

Identify the features present in animal cells

• nucleus

• central vacuole

• golgi apparatus

• rough ER

• centrioles

• choloroplasts

• mitochondria

nucleus, golgi apparatus, rough ER, centrioles, mitochondria

Lysosomes are membrane-bound vesicles that arise from the

golgi apparatus

The lysosome contains _________blank enzymes.

hydrolytic

Which of the following cells will be expected to contain the most active lysosomes?

• brain cell

• skin cell

• kidney cell

• intestinal cell

• phagocytosing white blood cell

phagocytosing white blood cell

What function do many B vitamins serve in the production of energy?

as coenzymes

Enzymes assist in the occurrence of chemical reactions by

lowering of activation rate

In the example shown, what coenzyme is used to assist in the production of ATP from pyruvate?

thiamine pyrophosphate

Consuming B vitamins in excess of need will

increase B vitamins in urine

Which B vitamin is found in egg yolks (and other foods) and functions as part of coenzyme A?

pantothenic acid

Nucleus’s function?

Stores and transmits genetic information in the form of DNA

nucleolus’s function?

Site of ribosomal RNA synthesis

ribosome’s function?

Protein factories of a cell

Rough endoplasmic reticulum/ER’s function?

Proteins synthesized on the attached ribosomes enter this organelle and are distributed to other organelles or secreted from the cell

Smooth endoplasmic reticulum/ER’s function?

Contains enzymes for fatty acid and steroid synthesis; stores and releases CA2+

Golgi apparatus

Concentrates, modifies, and sorts proteins arriving from the rough ER

Endosomes

Membrane-bound vesicular and tubular structures that assist the Golgi apparatus with sorting, modifying, and directing vesicular traffic in cells

mitochondria

Major site of ATP production, O2 utilization, and CO2 production

lysosomes

Break down bacteria and dead cell debris with acid and a variety of digestive enzymes

peroxisomes

Removes hydrogen from organic molecules including lipids, alcohol, and potentially toxic ingested substances

cytoskeleton

Associated with processes that maintain and change cell shape and produce cell movements

A(n) _______ is any molecule or ion that is bound to the surface of a protein.

ligand

The region of a protein to which a ligand binds is known as a

binding site

The ability of a protein-binding site to bind specific ligands is known as ________, and it depends only on the __________ of the binding site.

• chemical specificity

• shape

The strength of the attraction between the protein and the ligand is known as

affinity

Binding sites that tightly bind a ligand are called ________ binding sites.

high affinity

Binding sites that weakly bind a ligand are called _________ binding sites.

low affinity

The fraction of total binding sites that are occupied at any given time is known as

saturation

When multiple ligands are available that can bind to the same binding site, ________ can occur

competition

What was the physiological cause of the man's muscle weakness?

skeletal muscle cells were dying and releasing their contents into the blood

What was causing the man's muscle cells to rupture?

excess blood concentration of the statin drug

What was the cause of the dark color of the patient's urine?

the breakdown products from ruptured skeletal muscle cells was filtering through the kidneys into the urine

How did the man's increase in grapefruit juice intake trigger his condition?

it inhibited the enzyme CYP3A4 from removing the statin drug from his system at a normal rate

In addition to carbon, hydrogen, and oxygen atoms, amino acids contain _________ atoms in their amino groups.

nitrogen

Once the ___________ is removed, the remainder of most amino acids can be metabolized to intermediates that enter the glycolytic pathway or Krebs cycle.

amino group

Two reactions where the amino group can be removed are _________ and transamination

oxidative deamination

In the former reaction, the amino group converts to a molecule of ________ and is replaced by an ________ atom derived from water.

• ammonia (NH₃)

• oxygen

The amino acid with its amino group removed is now known as a(n)

keto acid

In __________, there is transfer of the amino group from an __________ to a keto acid, which then becomes an amino acid.

• transamination

• amino acid

Finally, the ammonia produced by oxidative deamination is carried by the blood to the _________ where it is converted to ________, which can be excreted by the _________

• liver

• urea

• kidneys

Which is a major function of the plasma membrane?

regulating the passage of molecules into and out the cell

Macrophages are cells that engulf and digest bacteria and cell debris. To perform the digestive function, macrophages tend to have more _________blank than other cells.

lysosomes

Which of these are functions of the Golgi apparatus?

• modifying proteins synthesized on free ribosomes and storing calcium ions

• digestion of engulfed bacteria and using oxygen to generate ATP

• synthesizing lipids and intracellular storage of calcium ions

• modifying proteins synthesized on ribosomes associated with granular endoplasmic reticulum and allowing the distribution of modified proteins throughout the cell in vesicles

modifying proteins synthesized on ribosomes associated with granular endoplasmic reticulum and allowing the distribution of modified proteins throughout the cell in vesicles

Which of the following is not true of the cytoskeleton?

to the cellular components of bone

The term "metabolism"

refers to the synthesis and breakdown of organic molecules involved in cell structures and function

Enzymes

are catalysts in chemical reactions

Which is a major function of the plasma membrane?

• storing calcium ions

• providing genetic information

• generating ATP

• regulating the passage of molecules into and out the cell

regulating the passage of molecules into and out the cell

The cell membrane is composed mainly of

phospholipids and proteins

Which best describes functions of the smooth (agranular) endoplasmic reticulum?

• transcription of DNA into RNA

• generation of ATP

• digestion of engulfed bacteria and cellular debris

• synthesis and packaging of proteins for secretion from the cell or export to other organelles

• synthesis of lipids and intracellular storage of calcium ions

synthesis of lipids and intracellular storage of calcium ions

Macrophages are cells that engulf and digest bacteria and cell debris. To perform the digestive function, macrophages tend to have more _________blank than other cells.

lysosomes

Which of these are functions of the Golgi apparatus?

• modifying proteins synthesized on free ribosomes and storing calcium ions

• digestion of engulfed bacteria and using oxygen to generate ATP

• synthesizing lipids and intracellular storage of calcium ions

• modifying proteins synthesized on free ribosomes and allowing the distribution of modified proteins throughout the cell in vesicles

• modifying proteins synthesized on ribosomes associated with granular endoplasmic reticulum and allowing the distribution of modified proteins throughout the cell in vesicles

modifying proteins synthesized on ribosomes associated with granular endoplasmic reticulum and allowing the distribution of modified proteins throughout the cell in vesicles

Neurons have a very prominent nucleolus, which indicates that they are actively performing what function?

manufacturing ribosomes

Which is the best definition of the term ligand?

• a receptor composed of protein

• a molecule or ion that binds to a protein

• any molecule found in the intracellular fluid

• any molecule found in the extracellular fluid

• a carbohydrate molecule that binds weakly to membrane phospholipids

a molecule or ion that binds to a protein

In skeletal muscle, when calcium binds to the regulatory protein troponin, it increases the affinity of neighboring troponin molecules for calcium. This is an example of

cooperativity

The term "metabolism"

refers to the synthesis and breakdown of organic molecules involved in cell structure and function.

How does a chemical catalyst increase the rate of a reaction?

by decreasing the energy of activation

What is a coenzyme?

an organic cofactor that directly participates as one of the substrates in an enzymatic reaction

ATP is

used to transfer energy within a cell.

The site where most of the ATP is generated in a cell is the

mitochondria.

Which is TRUE about glycolysis?

• It does not occur in the absence of O2.

• It does not occur in the presence of O2.

• It may result in the formation of two molecules of lactate for each molecule of glucose.

• It is a series of metabolic reactions that occur mainly inside the inner membrane of a mitochondrion.

• It is a metabolic reaction in which glucose is manufactured from large carbohydrates like glycogen.

It may result in the formation of two molecules of lactate for each molecule of glucose.

Which of these covalently modifies proteins by phosphorylation?

• enzymes called protein phosphatases

• other proteins called allosteric proteins

• any ligand that can bind to specific binding sites

• enzymes called protein kinases

• metal ions, such as Fe2+

enzymes called protein kinases

What is the function of a catalyst in a chemical reaction?

It lowers the activation energy of the reaction.

The reactions of the Krebs cycle

generate ATP directly by substrate-level phosphorylation

True or False

Lysosomes function in the destruction and recycling of old organelles

True

As a graduate teaching assistant for your physiology class, you are required to provide an evaluation of the following examples of student work regarding cellular structure. No two answers can have the same grade assigned. A, C, or F

1. Cells are surrounded by a plasma membrane, which encloses the organelles and cytosol. All fluids found inside the plasma membrane, including fluid in the organelles is known as intracellular fluid, which in total makes up about 2/3 of the entire weight of the body. Theoretically, if the nucleus enlarged with no change in the cell volume, the ICF of the cell would not change.

A

As a graduate teaching assistant for your physiology class, you are required to provide an evaluation of the following examples of student work regarding cellular structure. No two answers can have the same grade assigned. A, C, or F

2. Inside the plasma membrane are the nucleus of the cell, other organelles, and a sometimes protein-rich fluid known as the cytoplasm. Theoretically, if the cell increased its mitochondrial density with no change in cell volume, the cytoplasmic volume would be increased. Of all bodily water, most are found enclosed by the plasma membranes of the body.

C

As a graduate teaching assistant for your physiology class, you are required to provide an evaluation of the following examples of student work regarding cellular structure. No two answers can have the same grade assigned. A, C, or F

3. The interior of a cell is comprised of the nucleus and the cytosol while the cytosol is divided between the cytoplasm and the remainder of the organelles. Theoretically, if the overall volume of the cytosol increased without altering the cell volume, the size and/or number of organelles must increase as well.

F