CH 1: Normal Cellular Biology

Question 1

What are the five functions of a cell?

Answer 1

Movement
* Conductivity
* Metabolic absorption
* Secretion
* Excretion
* Respiration
* Reproduction
* Communication

Question 2

Endoplasmic reticulum
– Structure: Network of tubular or saclike channels;
smooth vs. rough endoplasmic reticulum
– Function: Site of protein synthesis; senses cellular
stress

Question 3

Ribosomes are
nucleoproteins that
1. are synthesized in the
mitochondria and
secreted into the
cytosol.
2. are synthesized in the
cytoplasm.
3. consist of a network of
cisternae.
4. synthesize a signal
recognition sequence.

Answer 3

ANS 4: Newly formed ribosomes
synthesize a signal recognition sequence
recognized by particles in the cytosol.
* 1. Ribosomes are synthesized in the
nucleolus.
* 2. Ribosomes are synthesized in the
nucleolus.
* 3. The endoplasmic reticulum is
composed of cisternae.

Question 4

Golgi complex
– Structure
* Flattened, smooth membranes
* Secretory vesicles and cisternae
* Proteins from the endoplasmic reticulum that are
packaged in the Golgi complex
* Clathrin-coated vesicles
– Functions
* “Refining plant” and directs traffic
* Processes, secretes, and releases substances,
especially protein from cells

Question 5

Mitochondria
– Structure
* Is surrounded by a double membrane.
* Increased inner membrane surface area is
provided by cristae.
– Functions
* Is responsible for cellular respiration and
energy production.
* Participates in oxidative phosphorylation.

Question 6

6 functions of plasma membranes?

Answer 6

Plasma membranes
– Control the composition of the space or
compartment they enclose.
– Enclose the cell.
– Provide the selective transport system.
– Provide cell-to-cell recognition.
– Provide cellular mobility and shape.
– Provide cell-to-cell recognition.

Question 7

The plasma membrane of a cell is
1. permeable to water
soluble molecules’
movement into the cell.
2. composed primarily of
amphipathic molecules.
3. dimpled because of
peripheral membrane
proteins.
4. impermeable to lipid-
soluble molecules

Answer 7

ANS: 2
* These molecules are polar with a
hydrophobic (uncharged, water
hating) portion and a hydrophilic
(charged, water loving) portion.
* 1. The plasma membrane is
impermeable to the movement of
water-soluble molecules into the
cell.
* 3. The plasma membrane is
dimpled because of the presence
of caveolae, cavelike indentations.
* 4. Lipid-soluble molecules like
oxygen diffuse readily through the
plasma membrane.

Question 9

Extracellular matrix
– Structure
* Meshwork of fibrous proteins in a watery, gel-like substance
of complex carbohydrates
* Macromolecules
– Collagen
– Elastin
– Fibronectin
– Proteoglycans
– Hyaluronic acid
* Fibroblasts
– Functions: Regulate cell growth, movement, and differentiation

Question 10

Cell-to-Cell Adhesions
Basement membrane (basal lamina)
– Thin, tough, flexible
– Lies beneath epithelial cells
– Surrounds individual cells
* Muscle, fat, Schwann cells

Question 11

Which information is correct
regarding neurotransmitters?
1. Act on the cells that produce
and secrete them.
2. Act on nearby cells that also
take them up and destroy
them.
3. Are produced by
neurosecretory neurons and
transmitted via the blood.
4. Diffuse across the synaptic
cleft and act on postsynaptic
target cell.

Answer 11

• ANS: 4
• Neurotransmitters are produced
  and released into the synaptic cleft
  and act on cells or receptors on the
  postsynaptic cell.
• 1. Signaling cells act on the cell
     that produces and secretes them
     by autocrine signaling.
• 2. In paracrine signaling, cellular
     mediators act on nearby cells.
• 3. Neurohormonal signaling is
     produced by blood-borne
     transmission of the products of
     neurosecretory neurons.

Question 12

Metabolism
– Chemical tasks of maintaining essential
cellular functions
– Provides the cell with energy.
– Anabolism
* Energy using
– Catabolism
* Energy releasing

Question 13

Role of ATP
– Is created from the chemical energy
contained in organic molecules.
* When molecules of carbohydrate, lipid, and protein
are catabolized, this energy is transferred to ATP.
– Is used in the synthesis of organic molecules,
muscle contraction, and active transport.
– Functions
* Storage of energy
* Transfer of energy

Question 14

Food and production of cellular energy
– Digestion
– Glycolysis and oxidation
* Occurs in the cytoplasm
* Oxidative cellular metabolism
* Six ATP molecules for each molecule of glucose
– Citric acid cycle
* Is called Krebs cycle or the tricarboxylic acid (TCA)
cycle.
– Oxidative phosphorylation
* Occurs in the mitochondria; is the mechanism by which
energy produced from carbohydrates, fats, and proteins
is transferred to ATP.

Question 15

Passive Transport: (3)
Diffusion
* A solute is moved from an area of greater
concentration to an area of lesser concentration.
* The difference in concentration is known as a
concentration gradient.
* The rate of diffusion of a substance depends on its
size and lipid solubility.

Answer 15

Filtration: Hydrostatic pressure
* Water and solutes move through a membrane because
of a greater pushing pressure (force) on one side of the
membrane than on the other side.
– Osmosis
* Water moves “down” a concentration gradient.
* Osmotic pressure: The amount of hydrostatic pressure required to oppose the osmotic movement of water
* Oncotic pressure or colloid osmotic pressure: The overall osmotic effect of colloids, such as plasma
proteins

Question 16

Omsolarity (volume) vs. Omsolality (weight)

Answer 16

Tonicity
– Effective osmolality of a solution
* Isotonic: Same osmolality or concentration of
particles (285 mOsm/kg) as the intracellular fluid (ICF) or extracellular fluid (ECF)
* Hypertonic: Concentration of more than 285–294
mOsm/kg
* Hypotonic: Lower concentration; more dilute than body fluids

Question 17

A nurse practitioner knows that active transport requires:
1. receptors capable of
recognizing and binding with specific molecules.
2. a hydrostatic pressure
gradient between intracellular and extracellular regions.
3. a molecule bound to a ligand that moves the substance down the gradient.
4. the presence of pores in the cell membrane with no energy expenditure.

Answer 17

ANS: 1
* Active transport requires the use of
specific receptors matched with
molecules and the expenditure of
energy.
* 2. A hydrostatic pressure gradient
moves water by passive transport.
* 3. Molecules bound to a ligand may
use active transport, but ligand
binding is not mandatory and it
moves it up the gradient, not down.
* 4. Passive transport occurs through
pores in the cell membrane and
active transport requires energy.

Question 19

The cell Cycle:
* Necessary for life
* Reproduction of gametes: Meiosis
* Mitosis (nuclear) vs. cytokinesis (cytoplasmic)
* Chromatin vs. chromosomes vs. chromatids
* Interphase
– G1 phase—gap
– S phase—DNA synthesis
– G2 phase—RNA and protein synthesis
– M phase—mitosis occurs

Answer 19

4 Phases of Mitosis:
Mitosis is divided into four phases:
– Prophase
– Metaphase
– Anaphase
– Telophase
* Two identical diploid cells or daughter cells
are produced.

Question 20

4 types of tissue

Answer 20

Muscle
– Neural
– Epithelial
– Connective