PHGY 170: Key Themes - Midterm 1
Module 1: Key Themes
Cell Theory
➔ All living organisms are made up of one or more cells.
➔ The cell is the most basic unit of structure and organization in all living
organisms.
➔ All cells come from preexisting cells.
Key Properties That Allow Water to Support Life
➔ Polar properties: allows for the delivery of nutrients, removal of waste, and
provides an environment that allows cells to exist in a network by allowing
movement of chemical messengers.
➔ High specific heat capacity (SHC): for thermoregulation by acting as a heat sink
for the many chemical reactions that occur within cells, as well as the exchange
of heat between liquid and air.
Chemical Properties That Allow Carbon to Support Life
➔ It can create up to four covalent bonds with other molecules: can form a wide
variety of molecules important to cellular life.
➔ Small: allows it to comfortably form and bond with large molecules.
➔ Can form hydrocarbons: allows cells to form membranes and subcellular
compartmentalization.
Major Classes of Carbon-Based Macromolecules
➔ Carbohydrates
a. Hydrophilic
b. Monosaccharides; one
c. Disaccharides; 2 monosaccharides
d. Oligosaccharides; 3-10 monosaccharides
e. Polysaccharides; many monosaccharides
➔ Lipids
a. Hydrophobic
, b. Hydrocarbons/fatty acid chains (saturated or unsaturated)
c. Cholesterol, energy storage, hormonal messengers
d. Can be amphipathic - forms membranes
➔ Proteins
a. Hydrophilic polymers of amino acids
b. Composed of carboxyl group, amino acid, and a side chain
c. Bonds between side chains determine structure and function
➔ Nucleic Acids
a. Hydrophilic polymers of nucleotides
b. Carry genetic information
c. Composed of a nitrogenous base, pentose sugar, and 3 phosphate groups
Module 2: Key Themes
Structure and Function of the 5 Major Subcomponents of the Nucleus
Subcomponent Structure Function
The nuclear envelope has a The nuclear envelope
double membrane structure controls what molecules
Nuclear Envelope that encloses the nuclear have access to the nucleus
material. and separates the DNA from
other cell compartments.
The nuclear pores are The nuclear pores regulate
numerous layers of stacked molecule traffic in and out of
Nuclear Pores rings spanning the nuclear the nucleus. Small
envelope. molecules can pass through
freely. The nuclear pore
complexes regulate the
movement of large
molecules.
, The nucleolus is located The nucleolus creates
inside of the nucleus and is rRNAs and assembles them
made up of proteins and into ribosomal subunits
Nucleolus RNA. All nuclei contain at used by the cell to translate
least one nucleolus. proteins. It is also the site of
high amounts of rRNA gene
transcription and the DNA
that encodes these genes is
organized here.
The nucleoplasm is a The nucleoplasm contains
viscous, water-based fluid dissolved molecules and
that is enclosed in the ions that are essential for
nuclear membrane. The nucleus function. It helps
Nucleoplasm & Nuclear nuclear matrix is a network maintain shape and
Matrix of filaments within the structure of the nucleus and
nucleoplasm. serves as a suspension
substance for nuclear
contents.
The nuclear matrix helps
organize the DNA in
chromosomes into
compartments.
The chromatin is a complex Strands of DNA are
of DNA and proteins which organized and stored in
Chromosomes & Chromatin forms highly organized chromatin that make up
fibers. chromosomes.
Chromosomes are highly Chromosomes are only
condensed chromatin. found in the nucleus only
during cell division.
Differences between DNA Strands
➔ Leading Strand
a. Runs in the 3’ to 5’ direction.
Module 1: Key Themes
Cell Theory
➔ All living organisms are made up of one or more cells.
➔ The cell is the most basic unit of structure and organization in all living
organisms.
➔ All cells come from preexisting cells.
Key Properties That Allow Water to Support Life
➔ Polar properties: allows for the delivery of nutrients, removal of waste, and
provides an environment that allows cells to exist in a network by allowing
movement of chemical messengers.
➔ High specific heat capacity (SHC): for thermoregulation by acting as a heat sink
for the many chemical reactions that occur within cells, as well as the exchange
of heat between liquid and air.
Chemical Properties That Allow Carbon to Support Life
➔ It can create up to four covalent bonds with other molecules: can form a wide
variety of molecules important to cellular life.
➔ Small: allows it to comfortably form and bond with large molecules.
➔ Can form hydrocarbons: allows cells to form membranes and subcellular
compartmentalization.
Major Classes of Carbon-Based Macromolecules
➔ Carbohydrates
a. Hydrophilic
b. Monosaccharides; one
c. Disaccharides; 2 monosaccharides
d. Oligosaccharides; 3-10 monosaccharides
e. Polysaccharides; many monosaccharides
➔ Lipids
a. Hydrophobic
, b. Hydrocarbons/fatty acid chains (saturated or unsaturated)
c. Cholesterol, energy storage, hormonal messengers
d. Can be amphipathic - forms membranes
➔ Proteins
a. Hydrophilic polymers of amino acids
b. Composed of carboxyl group, amino acid, and a side chain
c. Bonds between side chains determine structure and function
➔ Nucleic Acids
a. Hydrophilic polymers of nucleotides
b. Carry genetic information
c. Composed of a nitrogenous base, pentose sugar, and 3 phosphate groups
Module 2: Key Themes
Structure and Function of the 5 Major Subcomponents of the Nucleus
Subcomponent Structure Function
The nuclear envelope has a The nuclear envelope
double membrane structure controls what molecules
Nuclear Envelope that encloses the nuclear have access to the nucleus
material. and separates the DNA from
other cell compartments.
The nuclear pores are The nuclear pores regulate
numerous layers of stacked molecule traffic in and out of
Nuclear Pores rings spanning the nuclear the nucleus. Small
envelope. molecules can pass through
freely. The nuclear pore
complexes regulate the
movement of large
molecules.
, The nucleolus is located The nucleolus creates
inside of the nucleus and is rRNAs and assembles them
made up of proteins and into ribosomal subunits
Nucleolus RNA. All nuclei contain at used by the cell to translate
least one nucleolus. proteins. It is also the site of
high amounts of rRNA gene
transcription and the DNA
that encodes these genes is
organized here.
The nucleoplasm is a The nucleoplasm contains
viscous, water-based fluid dissolved molecules and
that is enclosed in the ions that are essential for
nuclear membrane. The nucleus function. It helps
Nucleoplasm & Nuclear nuclear matrix is a network maintain shape and
Matrix of filaments within the structure of the nucleus and
nucleoplasm. serves as a suspension
substance for nuclear
contents.
The nuclear matrix helps
organize the DNA in
chromosomes into
compartments.
The chromatin is a complex Strands of DNA are
of DNA and proteins which organized and stored in
Chromosomes & Chromatin forms highly organized chromatin that make up
fibers. chromosomes.
Chromosomes are highly Chromosomes are only
condensed chromatin. found in the nucleus only
during cell division.
Differences between DNA Strands
➔ Leading Strand
a. Runs in the 3’ to 5’ direction.
