N2060 2020
Patho: Chapters 1, 2, 3 Study Objectives
CHAPTER 1
1. Compare and contrast the two major classes of living cells.
2. Prokaryotes:
a. Structure:
i. Lack of distinct nucleus
ii. Nuclear material is not encased by a nuclear membrane
iii. No organelles
iv. Examples: fungi, protozoa, most algae; cyanobacteria (blue-green algae), bacteria, Rickettsiae
b. Chemical Composition and Biochemical Activity:
i. Nuclei carry genetic information in a single circular chromosome
ii. Lack histones (class of proteins)
iii. Protein production differs due to structural differences in RNA protein complexes
iv. Differences in mechanisms of transport
v. Differences in enzyme content
3. Eukaryotes:
a. Structure:
i. Larger
ii. Well defined nucleus
iii. Characteristic set of membrane bound organelles
iv. Complex cellular organization
v. Examples: Higher animals and plants, fungi, protozoa
b. Chemical Composition and Biochemical Activity:
i. Have several chromosomes
ii. Histones in eukaryotic cells bind with DNA (loops and coiling of DNA are important for many diseases)
iii. Protein production differs due to structural differences in RNA protein complexes
iv. Differences in mechanisms of transport
v. Differences in enzyme content
1. Describe and provide examples of the eight major cellular functions: movement, conductivity, absorption, secretion, excretion, respiration,
reproduction, and communication.
Cells become specialized through the process of differentiation or maturation
1. Movement: Muscle cells can generate forces that produce motion. Muscles that are attached to bones produce limb movements,
whereas those that enclose hollow tubes or cavities move or empty contents when they contract.
○ Example: The contraction of smooth muscle cells surrounding blood vessels changes the diameter of the vessels; the
contraction of muscles in the walls of the urinary bladder expels urine.
2. Conductivity: Conduction as a response to a stimulus is manifested by a wave of excitation, an electrical potential that passes along th
surface of the cell to reach its other parts. Conductivity is the chief function of nerve cells.
3. Metabolic absorption: All cells take in and use nutrients and other substances from their surroundings. Cells of the intestine and the
kidney are specialized to carry out absorption. Cells of the kidney tubules reabsorb fluids and synthesize proteins. Intestinal epithelial
cells reabsorb fluids and synthesize protein enzymes.
4. Secretion: Certain cells (ie. mucous gland cells) can synthesize new substances from substances they absorb and then secrete the new
substances to serve as needed elsewhere. Cells of the adrenal gland, testis, and ovary can secrete hormonal steroids.
5. Excretion: All cells can rid themselves of waste products resulting from the metabolic breakdown of nutrients. Membrane-bound sacs
(lysosomes) within cells contain enzymes that break down, or digest, large molecules, turning them into waste products that are relea
, from the cell.
6. Respiration: Cells absorb oxygen, which is used to transform nutrients into energy in the form of ATP. Cellular respiration, or oxidation
occurs in organelles called mitochondria.
7. Reproduction: Tissue growth occurs as cells enlarge and reproduce themselves. Even without growth, tissue maintenance requires tha
new cells are produced to replace cells that are lost normally through cellular death. Not all cells are capable of continuous division.
8. Communication: communication is vital for cells to survive as a society of cells. Pancreatic cells, for instance, secrete and release insul
necessary to signal muscle cells to absorb sugar from the blood for energy. Constant communication allows the maintenance of a
dynamic steady state.
2. Identify and describe the three principal parts of a typical eukaryotic cell.
Three general components:
1. Plasma membrane or Plasmalemma: Outer membrane
2. Cytoplasm: Aqueous solution (cytosol) that fills the cytoplasmic matrix (the space between the nuclear envelope and the plasma
membrane). Represents about half the volume of a eukaryotic cell and contains thousands of enzymes involved in intermediate
metabolism and is crowded with ribosomes that make proteins.
○ Main site for protein synthesis and degradation
■ Newly synthesized proteins remain in the cytosol if they lack a sorting signal for transport
○ Cytosol functions as a storage unit for fat, carbohydrate and secretory vesicles.
3. Intracellular organelles: Membrane bound and include the nucleus
3. Describe the location and function of the nucleus and the cytoplasmic organelles.
● Nucleus:
○ Surrounded by the cytoplasm and is generally located in the center of the cell.
○ Primary Functions: Cell division and control of genetic information
■ Other functions:
● Replication and repair of DNA
● Transcription of the information stored in DNA.
○ Genetic information is transcribed into RNA
■ Processed into messenger, transport and ribosomal RNA and introduced into the
cytoplasm where it directs cellular activities. Most RNA processing occurs in the
nucleolus.
○ Structure:
■ Nucleus is the largest membrane-bound organelle.
■ Nuclear envelope composed of two pliable membranes.
● Has nuclear pores
■ Nuclear pore complexes: allow molecules to move between the nucleus and the cytosol
■ Nucleolus: small, dense structure composed largely of RNA; most of the cellular DNA; and the DNA-binding protein
histones, that regulate its activity.
■ RNA
■ DNA: the DNA chain in eukaryotic cells is so extensive that the risk of breakage is high which is why folding is key.
■ Histone proteins: bind to DNA causing DNA to fold into chromosomes. The wrapping of DNA into tight packages o
chromosomes is essential for cell division in eukaryotes.
● Endoplasmic Reticulum:
○ Network of tubular channels (cisternae) that extends throughout the outer nuclear membrane
○ Specializes in the synthesis and transport of protein and lipid components of most of the organelles
○ Responsible for protein folding and sensing cell stress
● Golgi Complex:
○ Network of smooth membranes and vesicles located near the nucleus.
○ Responsible for processing and packaging proteins into secretory vesicles that break away from the Golgi complex and migra
to a variety of intracellular and extracellular destinations including the plasma membrane
● Lysosomes:
○ Saclike structures that originate from the Golgi complex and contain digestive enzymes. Digestive enzymes are responsible f
digesting most cellular substances completely to their basic components such as AA, fatty acids and carbs.
, ○ Also play a role in nutrient dependent signal transduction. Signaling function cooperates with the known degradative role to
mediate basic cell functions, such as nutrient sensing, metabolic adaptation and quality control of proteins and organelles.
○ 4 pathways of degradation in lysosomes include: endocytosis, phagocytosis, macropinocytosis and autophagy.
● Peroxisomes:
○ Similar to lysosomes but contain several oxidative enzymes such as catalase and urate oxidase.
● Mitochondria:
○ Found in great numbers in most cells
○ Responsible for cellular respiration and energy production
○ Enzymes of the respiratory chain (electron-transport chain), found in the inner membrane of the mitochondria, generate mo
of the cell’s ATP.
● Cytoskeleton:
○ Bone and muscle of the cell
○ Internal skeleton is composed of a network of protein filaments including microtubules and actin filaments (microfilaments)
4. Describe the structure, composition, and function of the plasma membrane.
Structure:
● Membrane Composition:
○ Bilayer of lipids and proteins not uniformly distributed
■ Provides fluid structure of membrane
■ Mostly an impermeable barrier to water soluble molecules
■ Caveolae
○ Lipids
■ Amphipathic: hydrophilic and hydrophobic
● Functions:
○ Table 1.1 in text
○ Structure
○ Protection
○ Activation of cell
○ Transport
○ Cell-to-cell interaction
5. Identify the location and main functions of plasma membrane proteins.
1. Location:
■ Transmembrane proteins extend across the bilayer and are exposed to an aqueous environment on both sides
■ Proteins located almost entirely in the cytosol and associated with the cytosolic half of the lipid bilayer by an alpha helix
exposed on the surface of the protein
■ Proteins existing outside the bilayer, on one side or the other, and attached to the membrane by one or more covalently
attached lipid groups.
2. Functions of membrane proteins
■ Membrane functions are determined largely by proteins.
■ a) recognition and binding units (receptors) for substances moving in and out of the cell
■ b) pores or transport channels for various electrically charged particles called ions or electrolytes and specific carriers for am
acids and monosaccharides
■ c) specific enzymes that drive active pumps that promote concentration of certain ions (ie. K+) within the cell while keeping
concentrations of other ions (ie. Na+) below concentrations in the extracellular environment/ECF.
■ d) cell surface markers, such as glycoproteins
■ e) cell adhesion molecules allow cells to hook together and form attachments to the cytoskeleton to maintain cell shape
■ f) catalysts of chemical reactions
● Example: converting lactose to glucose, chemical energy to electrical energy, electrical energy to mechanical energ
3. Proteins bound indirectly to one or the other bilayer membrane face and held in place by their interactions with other proteins.
6. Compare and contrast the three mechanisms that bind cells together: extracellular matrix, cell adhesion molecules, and specialized cell
junctions.
1. Extracellular matrix:
■ Intricate meshwork of interstitial fibrous proteins embedded in a watery, gel-like substance composed of complex carbs.
■ Cells can be bound together by attachment to one another or through the ECM (including the basement membrane) which
the cells secrete around themselves.
Patho: Chapters 1, 2, 3 Study Objectives
CHAPTER 1
1. Compare and contrast the two major classes of living cells.
2. Prokaryotes:
a. Structure:
i. Lack of distinct nucleus
ii. Nuclear material is not encased by a nuclear membrane
iii. No organelles
iv. Examples: fungi, protozoa, most algae; cyanobacteria (blue-green algae), bacteria, Rickettsiae
b. Chemical Composition and Biochemical Activity:
i. Nuclei carry genetic information in a single circular chromosome
ii. Lack histones (class of proteins)
iii. Protein production differs due to structural differences in RNA protein complexes
iv. Differences in mechanisms of transport
v. Differences in enzyme content
3. Eukaryotes:
a. Structure:
i. Larger
ii. Well defined nucleus
iii. Characteristic set of membrane bound organelles
iv. Complex cellular organization
v. Examples: Higher animals and plants, fungi, protozoa
b. Chemical Composition and Biochemical Activity:
i. Have several chromosomes
ii. Histones in eukaryotic cells bind with DNA (loops and coiling of DNA are important for many diseases)
iii. Protein production differs due to structural differences in RNA protein complexes
iv. Differences in mechanisms of transport
v. Differences in enzyme content
1. Describe and provide examples of the eight major cellular functions: movement, conductivity, absorption, secretion, excretion, respiration,
reproduction, and communication.
Cells become specialized through the process of differentiation or maturation
1. Movement: Muscle cells can generate forces that produce motion. Muscles that are attached to bones produce limb movements,
whereas those that enclose hollow tubes or cavities move or empty contents when they contract.
○ Example: The contraction of smooth muscle cells surrounding blood vessels changes the diameter of the vessels; the
contraction of muscles in the walls of the urinary bladder expels urine.
2. Conductivity: Conduction as a response to a stimulus is manifested by a wave of excitation, an electrical potential that passes along th
surface of the cell to reach its other parts. Conductivity is the chief function of nerve cells.
3. Metabolic absorption: All cells take in and use nutrients and other substances from their surroundings. Cells of the intestine and the
kidney are specialized to carry out absorption. Cells of the kidney tubules reabsorb fluids and synthesize proteins. Intestinal epithelial
cells reabsorb fluids and synthesize protein enzymes.
4. Secretion: Certain cells (ie. mucous gland cells) can synthesize new substances from substances they absorb and then secrete the new
substances to serve as needed elsewhere. Cells of the adrenal gland, testis, and ovary can secrete hormonal steroids.
5. Excretion: All cells can rid themselves of waste products resulting from the metabolic breakdown of nutrients. Membrane-bound sacs
(lysosomes) within cells contain enzymes that break down, or digest, large molecules, turning them into waste products that are relea
, from the cell.
6. Respiration: Cells absorb oxygen, which is used to transform nutrients into energy in the form of ATP. Cellular respiration, or oxidation
occurs in organelles called mitochondria.
7. Reproduction: Tissue growth occurs as cells enlarge and reproduce themselves. Even without growth, tissue maintenance requires tha
new cells are produced to replace cells that are lost normally through cellular death. Not all cells are capable of continuous division.
8. Communication: communication is vital for cells to survive as a society of cells. Pancreatic cells, for instance, secrete and release insul
necessary to signal muscle cells to absorb sugar from the blood for energy. Constant communication allows the maintenance of a
dynamic steady state.
2. Identify and describe the three principal parts of a typical eukaryotic cell.
Three general components:
1. Plasma membrane or Plasmalemma: Outer membrane
2. Cytoplasm: Aqueous solution (cytosol) that fills the cytoplasmic matrix (the space between the nuclear envelope and the plasma
membrane). Represents about half the volume of a eukaryotic cell and contains thousands of enzymes involved in intermediate
metabolism and is crowded with ribosomes that make proteins.
○ Main site for protein synthesis and degradation
■ Newly synthesized proteins remain in the cytosol if they lack a sorting signal for transport
○ Cytosol functions as a storage unit for fat, carbohydrate and secretory vesicles.
3. Intracellular organelles: Membrane bound and include the nucleus
3. Describe the location and function of the nucleus and the cytoplasmic organelles.
● Nucleus:
○ Surrounded by the cytoplasm and is generally located in the center of the cell.
○ Primary Functions: Cell division and control of genetic information
■ Other functions:
● Replication and repair of DNA
● Transcription of the information stored in DNA.
○ Genetic information is transcribed into RNA
■ Processed into messenger, transport and ribosomal RNA and introduced into the
cytoplasm where it directs cellular activities. Most RNA processing occurs in the
nucleolus.
○ Structure:
■ Nucleus is the largest membrane-bound organelle.
■ Nuclear envelope composed of two pliable membranes.
● Has nuclear pores
■ Nuclear pore complexes: allow molecules to move between the nucleus and the cytosol
■ Nucleolus: small, dense structure composed largely of RNA; most of the cellular DNA; and the DNA-binding protein
histones, that regulate its activity.
■ RNA
■ DNA: the DNA chain in eukaryotic cells is so extensive that the risk of breakage is high which is why folding is key.
■ Histone proteins: bind to DNA causing DNA to fold into chromosomes. The wrapping of DNA into tight packages o
chromosomes is essential for cell division in eukaryotes.
● Endoplasmic Reticulum:
○ Network of tubular channels (cisternae) that extends throughout the outer nuclear membrane
○ Specializes in the synthesis and transport of protein and lipid components of most of the organelles
○ Responsible for protein folding and sensing cell stress
● Golgi Complex:
○ Network of smooth membranes and vesicles located near the nucleus.
○ Responsible for processing and packaging proteins into secretory vesicles that break away from the Golgi complex and migra
to a variety of intracellular and extracellular destinations including the plasma membrane
● Lysosomes:
○ Saclike structures that originate from the Golgi complex and contain digestive enzymes. Digestive enzymes are responsible f
digesting most cellular substances completely to their basic components such as AA, fatty acids and carbs.
, ○ Also play a role in nutrient dependent signal transduction. Signaling function cooperates with the known degradative role to
mediate basic cell functions, such as nutrient sensing, metabolic adaptation and quality control of proteins and organelles.
○ 4 pathways of degradation in lysosomes include: endocytosis, phagocytosis, macropinocytosis and autophagy.
● Peroxisomes:
○ Similar to lysosomes but contain several oxidative enzymes such as catalase and urate oxidase.
● Mitochondria:
○ Found in great numbers in most cells
○ Responsible for cellular respiration and energy production
○ Enzymes of the respiratory chain (electron-transport chain), found in the inner membrane of the mitochondria, generate mo
of the cell’s ATP.
● Cytoskeleton:
○ Bone and muscle of the cell
○ Internal skeleton is composed of a network of protein filaments including microtubules and actin filaments (microfilaments)
4. Describe the structure, composition, and function of the plasma membrane.
Structure:
● Membrane Composition:
○ Bilayer of lipids and proteins not uniformly distributed
■ Provides fluid structure of membrane
■ Mostly an impermeable barrier to water soluble molecules
■ Caveolae
○ Lipids
■ Amphipathic: hydrophilic and hydrophobic
● Functions:
○ Table 1.1 in text
○ Structure
○ Protection
○ Activation of cell
○ Transport
○ Cell-to-cell interaction
5. Identify the location and main functions of plasma membrane proteins.
1. Location:
■ Transmembrane proteins extend across the bilayer and are exposed to an aqueous environment on both sides
■ Proteins located almost entirely in the cytosol and associated with the cytosolic half of the lipid bilayer by an alpha helix
exposed on the surface of the protein
■ Proteins existing outside the bilayer, on one side or the other, and attached to the membrane by one or more covalently
attached lipid groups.
2. Functions of membrane proteins
■ Membrane functions are determined largely by proteins.
■ a) recognition and binding units (receptors) for substances moving in and out of the cell
■ b) pores or transport channels for various electrically charged particles called ions or electrolytes and specific carriers for am
acids and monosaccharides
■ c) specific enzymes that drive active pumps that promote concentration of certain ions (ie. K+) within the cell while keeping
concentrations of other ions (ie. Na+) below concentrations in the extracellular environment/ECF.
■ d) cell surface markers, such as glycoproteins
■ e) cell adhesion molecules allow cells to hook together and form attachments to the cytoskeleton to maintain cell shape
■ f) catalysts of chemical reactions
● Example: converting lactose to glucose, chemical energy to electrical energy, electrical energy to mechanical energ
3. Proteins bound indirectly to one or the other bilayer membrane face and held in place by their interactions with other proteins.
6. Compare and contrast the three mechanisms that bind cells together: extracellular matrix, cell adhesion molecules, and specialized cell
junctions.
1. Extracellular matrix:
■ Intricate meshwork of interstitial fibrous proteins embedded in a watery, gel-like substance composed of complex carbs.
■ Cells can be bound together by attachment to one another or through the ECM (including the basement membrane) which
the cells secrete around themselves.
