BIOL 1441 CELL AND MOLECULAR BIOLOGY
complete notes all what you need to know 2025
University of Texas, Arlington
Biology notes:
Chapter 1: The biology of you
Cell -> tissue -> organ -> organ system-> organism
Catabolic VS Anabolic
Catabolic: the breaking down of complex molecules in organisms
Anabolic: the building up of complex molecules in an organism
4 common things in all cells:
1. Plasma membrane
a. The outer covering the cell from the surrounding environment.
2. Cytoplasm
a. The jelly-like substance within the cell that helps suspend the
cellular components.
3. DNA and RNA
a. The genetic material of the cell
4. Ribosomes
a. The substance within the cell that synthesizes protein
Cell classification Description
Prokaryotic • Simple, single celled
• Unicellular (no nucleus)
• No membrane- bound
organelles
• Ex: bacteria
Eukaryotic • Membrane-bound organelles/
organelles with specialized
functions.
• Contains nucleus
• Ex: tissue
Biological Macromolecules
These are what organisms are made of. They are organic, which means they
contain carbon and hydrogen. A macromolecule is made up of smaller
subunits called monomers,
,4 major classes of biological macromolecules
1) Carbohydrates
2) Lipids
3) Proteins
4) Nucleic acid
Macromole Monomers Functions Examples
cules
Carbohydrat Sugar • Store energy Potato
es • Structural Material
Lipids Fatty Acid • Store energy Fat cells
• Form membrane
• Steroids
• Hormones
• Cholesterol
Proteins Amino Acid • Enzymes Hair
• Structural material
Peptides
• Peptides
Nucleic Acid Nucleotide • Store genetic DNA
information
Carbohydrates
• They are classified into 3 subtypes: monosaccharides, disaccharides,
and polysaccharides
o Monosaccharides
▪ Simple sugars (glucose) C6H12O6
▪ The number of carbon atoms range from 3 to 6
▪Depending on the amount of sugar they may be known as
trioses (three carbon atoms), pentoses (five carbon
atoms), and hexoses (six carbon atoms)
▪ Glucose, galactose, and fructose are all monosaccharides
o Disaccharides
▪ Di=2
▪ Forms when 2 monosaccharides undergo a dehydration
reaction
• A reaction in which the removal of a water molecule
▪ Lactose, Maltose, and Sucrose are all disaccharides
, o Polysaccharides
▪ Poly=many
▪ A long chain of monosaccharides linked by covalent bonds
▪ Chain may be branched or unbranched and may contain
different types of monosaccharides
▪ Starch, glycogen, and cellulose are examples of
polysaccharides
• Starch
o Stored form of sugars in plants and include
amylose and amylopectin which are polymers
(chains of repeating subunits) of glucose.
• Glycogen
o Stored form of glucose in humans and other
vertebrates.
o Animal equivalent of starch and a highly
branched molecule usually stored in the liver
and muscle cells.
o When glucose levels decrease, glycogen is
broken down to release glucose.
• Cellulose
o One of the most abundant natural polymers
Lipids
• They are hydrophobic
• Perform many functions within a cell
• Help provide insulation from the environment for plants and animals
• They are the building blocks of many hormones and are important
part of the plasma membrane
• Fats, oils, waxes, phospholipids, and steroids are examples of lipids.
o Fat
▪ Consists of glycerol and fatty acids
• Glycerol
o A hydrophilic molecule with three carbon
atoms
• Fatty acids
o Long chain of hydrocarbons to which an acidic
carboxyl group is attached
o Comes in both saturated and unsaturated fat
▪ Saturated fatty acid
, • Single bond between neighboring
carbons in the hydrocarbon chain
• Saturated with hydrogen
• Tightly packed and are solid at
room temperature
▪ Unsaturated fatty acid
• Have characteristics with bends or
kinks in the chain
• Fatty acids are not packed tightly
and kept at room temperature
• Olive oil, corn oil, canola oil, and
cod liver oil are examples of
unsaturated fat
▪ Phospholipids
• They are the main constitute of the
plasma membrane
• They are composed of a fatty acid
chain attached to a glycerol.
• Instead of three fatty acids, there
are two fatty acid chains and a
third carbon of glycerol that is
bound to a phosphate acid group.
• The fatty acid chains are
hydrophobic and hydrophilic,
whereas phosphate is hydrophilic
and interacts with water.
• Cells are surrounded by a
membrane, which has a bilayer of
phospholipids,
▪ Steroids
• Steroids have a ring structure
• All steroids have 4 linked carbon
rings and several of them like
cholesterol, have a short tail.
o Cholesterol
▪ Cholesterol is a type of
steroid
▪ Is the precursor of bile
salts
complete notes all what you need to know 2025
University of Texas, Arlington
Biology notes:
Chapter 1: The biology of you
Cell -> tissue -> organ -> organ system-> organism
Catabolic VS Anabolic
Catabolic: the breaking down of complex molecules in organisms
Anabolic: the building up of complex molecules in an organism
4 common things in all cells:
1. Plasma membrane
a. The outer covering the cell from the surrounding environment.
2. Cytoplasm
a. The jelly-like substance within the cell that helps suspend the
cellular components.
3. DNA and RNA
a. The genetic material of the cell
4. Ribosomes
a. The substance within the cell that synthesizes protein
Cell classification Description
Prokaryotic • Simple, single celled
• Unicellular (no nucleus)
• No membrane- bound
organelles
• Ex: bacteria
Eukaryotic • Membrane-bound organelles/
organelles with specialized
functions.
• Contains nucleus
• Ex: tissue
Biological Macromolecules
These are what organisms are made of. They are organic, which means they
contain carbon and hydrogen. A macromolecule is made up of smaller
subunits called monomers,
,4 major classes of biological macromolecules
1) Carbohydrates
2) Lipids
3) Proteins
4) Nucleic acid
Macromole Monomers Functions Examples
cules
Carbohydrat Sugar • Store energy Potato
es • Structural Material
Lipids Fatty Acid • Store energy Fat cells
• Form membrane
• Steroids
• Hormones
• Cholesterol
Proteins Amino Acid • Enzymes Hair
• Structural material
Peptides
• Peptides
Nucleic Acid Nucleotide • Store genetic DNA
information
Carbohydrates
• They are classified into 3 subtypes: monosaccharides, disaccharides,
and polysaccharides
o Monosaccharides
▪ Simple sugars (glucose) C6H12O6
▪ The number of carbon atoms range from 3 to 6
▪Depending on the amount of sugar they may be known as
trioses (three carbon atoms), pentoses (five carbon
atoms), and hexoses (six carbon atoms)
▪ Glucose, galactose, and fructose are all monosaccharides
o Disaccharides
▪ Di=2
▪ Forms when 2 monosaccharides undergo a dehydration
reaction
• A reaction in which the removal of a water molecule
▪ Lactose, Maltose, and Sucrose are all disaccharides
, o Polysaccharides
▪ Poly=many
▪ A long chain of monosaccharides linked by covalent bonds
▪ Chain may be branched or unbranched and may contain
different types of monosaccharides
▪ Starch, glycogen, and cellulose are examples of
polysaccharides
• Starch
o Stored form of sugars in plants and include
amylose and amylopectin which are polymers
(chains of repeating subunits) of glucose.
• Glycogen
o Stored form of glucose in humans and other
vertebrates.
o Animal equivalent of starch and a highly
branched molecule usually stored in the liver
and muscle cells.
o When glucose levels decrease, glycogen is
broken down to release glucose.
• Cellulose
o One of the most abundant natural polymers
Lipids
• They are hydrophobic
• Perform many functions within a cell
• Help provide insulation from the environment for plants and animals
• They are the building blocks of many hormones and are important
part of the plasma membrane
• Fats, oils, waxes, phospholipids, and steroids are examples of lipids.
o Fat
▪ Consists of glycerol and fatty acids
• Glycerol
o A hydrophilic molecule with three carbon
atoms
• Fatty acids
o Long chain of hydrocarbons to which an acidic
carboxyl group is attached
o Comes in both saturated and unsaturated fat
▪ Saturated fatty acid
, • Single bond between neighboring
carbons in the hydrocarbon chain
• Saturated with hydrogen
• Tightly packed and are solid at
room temperature
▪ Unsaturated fatty acid
• Have characteristics with bends or
kinks in the chain
• Fatty acids are not packed tightly
and kept at room temperature
• Olive oil, corn oil, canola oil, and
cod liver oil are examples of
unsaturated fat
▪ Phospholipids
• They are the main constitute of the
plasma membrane
• They are composed of a fatty acid
chain attached to a glycerol.
• Instead of three fatty acids, there
are two fatty acid chains and a
third carbon of glycerol that is
bound to a phosphate acid group.
• The fatty acid chains are
hydrophobic and hydrophilic,
whereas phosphate is hydrophilic
and interacts with water.
• Cells are surrounded by a
membrane, which has a bilayer of
phospholipids,
▪ Steroids
• Steroids have a ring structure
• All steroids have 4 linked carbon
rings and several of them like
cholesterol, have a short tail.
o Cholesterol
▪ Cholesterol is a type of
steroid
▪ Is the precursor of bile
salts
