GENERAL BIOLOGY REVIEWER

LESSON 1: INTRODUCTION TO LESSON 2: CELL THEORY

BIOLOGY
Cell is the basic unit of life. An
Fun Facts: Organism is composed of one
or more cells. Human
1. Mycoplasma – smallest cell in
composed of Trillions of Cells
the world
and differentiate every system
2. Ovum/Egg cell – largest cell
in the body.
3. Neurons – Cells that cannot
be regenerate Cell Theory
4. White Blood Cells – fights
1. All living things are made up
pathogens
of one or more cells.
5. Red Blood Cells – carry
2. The cell is the basic unit of
oxygens through hemoglobin,
structure and function in living
no nucleus when matured, no
things.
mitochondria
3. All cells come from pre-
6. Sperm Cell – have
existing cells.
mitochondria
Discovery of Cells
Hierarchy of Life: Life is organized
from the smallest unit to the largest Robert Hooke (1665)
system:
1. Discovered cells while looking
1. Atom → basic unit of matter. at a thin slice of cork
2. Molecule → group of atoms 2. Describe the cells as
(e.g., water, DNA). honeycomb or tiny boxes
3. Organelle → parts of a cell 3. Thought that cells only existed
with specific functions (e.g., in plants and fungi.
nucleus, mitochondria).
4. Cell → basic unit of life. Anton van Leuwenhoek (1673)
5. Tissue → group of similar cells 1. Used a handmade microscope
working together. to observe pond scum &
6. Organ → group of tissues with discovered single-celled
a function. organisms He called them
7. Organ System → group of “animalcules”.
organs working together. 2. He also observed blood cells
8. Organism → one living from fish, birds, frogs, dogs,
individual. and humans. Therefore, it was
9. Population → group of same known that cells are found in
species in one area. animals as well as plants
10.Community → all different
populations in one area. Robert Brown
11.Ecosystem → community +
1. noticed that pollen grains in
nonliving environment (air,
water jiggled around called
water, soil).
“Brownian motion”
12.Biosphere → all ecosystems;
2. discovered nucleus
the zone of life on Earth.
Matthias Schleiden (1838)
Domains
Concluded that plants are composed
1. Prokaryo
of cells
2. Eukaryo
3. Bacteria Theodor Schwann (1839)
 GENERAL BIOLOGY REVIEWER
Concluded that animals are 2. Smooth ER – no ribosomes;
composed of cells makes lipids (fats) and
detoxifies.
Rudolf Virchow (1855)
Golgi Apparatus – packages, sorts,
1. A physician study cancer cell.
and delivers proteins and other
2. Conclude that “omins cellula e
molecules.
cellula” meaning all cells came
from pre-existing cells. Lysosomes – digest waste and
worn-out cell parts (“clean-up crew”).
Modern Cell Theory
Vacuole – storage for water, food,
1. The cell contains hereditary
and waste (larger in plant cells).
information (DNA) which is
passed on from cell to cell Chloroplasts (plants only) – do
during cell division. photosynthesis; make food from
2. All cells are basically the same sunlight.
in chemical composition and
Cell Wall (plants only) – rigid outer
metabolic activities.
layer for support and protection.
3. All basic chemical &
physiological functions are Cytoskeleton – gives shape,
carried out inside the cells. support, and helps with movement.
(movement, digestion,etc)
4. Cell activity depends on the Centrioles (animal cells only) –
activities of sub-cellular help in cell division.
structures within the cell LESSON 4: TYPES OF CELLS
(organelles, nucleus, plasma
membrane) Prokaryotic Cells: No nucleus or
membrane-bound organelles (e.g.,
LESSON 3: CELL STRUCTURE AND bacteria).
FUNCTIONS
Archaeal Cells: prokaryotes in
Cell Membrane (Plasma extreme environments, no
Membrane) – controls what enters peptidoglycan, unique membranes.
and exits the cell; protects the cell. (upgraded version of prokaryotes)
Cytoplasm – jelly-like fluid inside Eukaryotic Cells: Have a nucleus and
the cell where organelles are found. organelles (e.g., plant and animal
Nucleus – control center; contains cells).
DNA (genetic material). LESSON 5: CELL TYPES IN
Nucleolus – makes ribosomes TISSUES / SPECIALIZED CELLS
(inside nucleus). Tissue – made up of cells
Mitochondria – “powerhouse”; Animal Cells
produces energy (ATP).
1. Red Blood Cells: No nucleus
Ribosomes – make proteins (found when mature; carry oxygen.
on ER or floating in cytoplasm). 2. White Blood Cells: Defend
Endoplasmic Reticulum (ER) against pathogens.
3. Muscle Cells: Specialized for
1. Rough ER – with ribosomes; contraction; rich in
makes and transports mitochondria.
proteins.
 GENERAL BIOLOGY REVIEWER
4. Neurons: Long extensions for 2. Desmosomes – strong
transmitting signals. connections, keep cells from
5. Intestinal Cells: Have pulling apart.
microvilli to absorb nutrients. 3. Gap Junctions – small channels
for communication and
Plant Cells
transport between cells.
1. Guard Cells: Control stomata
LESSON 7: CELL CYCLE
opening/closing.
2. Root Hair Cells: Increase Mitosis
surface area for water
1. Produces identical diploid
absorption.
cells.
3. Xylem & Phloem: Transport
2. Phases: Prophase →
water and nutrients.
Metaphase → Anaphase →
4. Lignified Cells: Provide
Telophase.
structural support.
3. Interphase: DNA replication
LESSON 6: CELL MODIFICATIONS occurs here.
Cell modifications are the special gift Meiosis
for cells for beneficial ways.
1. Produces haploid gametes.
Apical Modifications (top surface 2. Increases genetic variation via
of the cell) crossing-over.
3. Important for sexual
1. Microvilli – increase surface
reproduction.
area for absorption (ex:
4. Phases: I and II (same division)
intestine).
2. Cilia – move substances across Diseases
the cell surface (ex:
Cancer cells – If the checkpoints
respiratory tract).
aren’t working the cell will turn into
3. Flagella – movement of the
cancer cells due to DNA mutations
whole cell (ex: sperm).
and caused malfunctions destroying
4. Pseudopods – Movement/Food
the host body. Also reducing the
capture
chance of diploid cells.
Basal Modifications (bottom
LESSON 8: CELL TRANSPORT
surface of the cell)
Cell transport = the movement of
1. Basement Membrane –
materials in and out of the cell
anchors the cell to underlying
through the cell membrane.
tissue.
2. Hemidesmosomes – attach the Passive Transport (no energy,
cell firmly to the basement moves from high → low
membrane. concentration)
Lateral Modifications (sides 1. Diffusion – movement of
between neighboring cells) molecules (like oxygen, CO₂)
from high to low
1. Tight Junctions – seal cells
concentration.
tightly together, prevent
2. Osmosis – movement of
leakage.
water through a semi-
permeable membrane.
 GENERAL BIOLOGY REVIEWER
3. Facilitated Diffusion – reactions), transport (hemoglobin),
diffusion with the help of defense (antibodies), movement
transport proteins. (actin, myosin).
Active Transport (needs Levels of structure: primary →
energy/ATP, moves from low → secondary → tertiary → quaternary
high concentration) (how proteins fold).
1. Protein Pumps – proteins Nucleic Acids – store and pass
push molecules against the genetic info
gradient.
1. DNA (Deoxyribonucleic
2. Endocytosis – cell “eats” or
Acid) – stores genetic
engulfs materials into vesicles.
instructions.
3. Phagocytosis = solid
2. RNA (Ribonucleic Acid) –
particles.
helps make proteins from DNA
4. Pinocytosis = liquids.
instructions.
5. Exocytosis – cell releases
3. Nucleotides – building blocks
materials outside using
(sugar + phosphate + base).
vesicles.
LESSO 9: BIOLOGICAL
MOLECULES
Biological Molecules
(Macromolecules)
Carbohydrates – sugars for energy
& structure
1. Monosaccharides – single
sugars (glucose, fructose).
2. Disaccharides – double
sugars (sucrose, lactose).
3. Polysaccharides – many
sugars (starch, glycogen,
cellulose, chitin).
Lipids – fats for energy storage,
insulation, membranes
1. Fats & Oils (Triglycerides) –
glycerol + 3 fatty acids;
energy storage.
2. Phospholipids – make up cell
membranes.
3. Steroids – hormones &
cholesterol.
4. Waxes – waterproof coatings.
Proteins – made of amino acids; do
most cell work
Functions: structural (keratin,
collagen), enzymes (speed up