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Cells
CELL WALL
 Rigid outer wall
 Gives plants support
 No skeleton
 Animal cells do not have cell
walls
 Flexibility
CELL WALL
Primary cell wall composed of…
 Cellulose
 Primary food source for grazers
 Also clothing, paper, furniture…
 Hemicellulose (glue)
 Pectin (stiffness of jelly)
 Glycoprotein (sugar protein)
CELL WALL
Secondary cell wall form inside the primary wall
 Mostly cellulose
 Lignins form like matrix for support
 Very rigid
Communication
 Tiny tunnels that allow for cells to
exchange “information”
 Plasmodesmata
 Plasmodesma (singular)
 Communication is carried out
with sugars, proteins, amino
acids, etc
Plasma Membrane
 The flexible membrane of
the living cell
 Plasma membrane
 Controls the movement of
materials in and out of cell
Cytoplasm
 Liquid inside cell
 Cytoplasm
 Mostly water
 Salts and proteins, too
Nucleus
 The control center
 Nucleus
 Contains DNA
 DNA is the blueprint of plant
biology
 Heritable traits
Nucleus
 DNA stored as chromosomes
 Nuclear envelope is porous
 Controls what comes in and
goes out
Endoplasmic Reticulum (ER)
 Directs traffic and activities
within the cell
 Endoplasmic Reticulum
 Primary site for the synthesis
of other organelles inside
cell
 Modifies proteins
Endoplasmic Reticulum (ER)
 Rough ER
 Ribosomes attached to surface
 Smooth ER
 Lacking ribosomes
Ribosomes
 Manufacturing complex
proteins
 Proteins are the basis of
living cells
 Communication
 The passing of
information (directions)
 Storage of information
 Catalysts
 Promote reactions
 Building proteins
Dictyosomes
 Flat stacks of organelles
throughout the cell
 Collecting, packaging and
delivering centers
 Post Offices
 Primarily modify proteins for
use within the cell
 Groups of dictyosomes
form the Golgi Apparatus
Mitochondria
 Powerhouse of the cell
 Mitochondria
 Mitochondrion (singular)
 Releases energy from organic
molecules
 These organelles float within
the cell
 Congregate where energy
needed
Mitochondria
 Inner folds
 Cristae
 Increased surface area for
activity
 MITOCHONDRIA
https://www.youtube.com/wat
ch?v=RrS2uROUjK4
Plastids
 A double membrane bound
organelle
 Involved in the synthesis
and storage of food
 Chloroplasts the most
common platid
 Photosynthesis
 Contain chlorophyll
Plastids
Chloroplast
 The liquid inside chloroplast
 Stroma
 Contains enzymes utilized in
photosynthesis
Plastids
Chloroplasts
 “Coins” perform photosynthesis
 Thylakoids
 A stack of thylakoids
 Granum
Plastids
 Chromoplast
 Involved in photosynthesis
 Carotenoid pigments create color
 Red, yellow, or orange
 Fruit and flowers
 Tomatoes, peppers
Plastids
 Leucoplasts are colorless plastids
 2 types of leucoplasts
 Amyloplasts
 Synthesize starches
 Elaioplasts
 Synthesize oils
Microbodies
 Granular bodies floating in
cytoplasm
 Peroxisomes
 Produce enzymes to survive heat
 Glyoxisomes
 Convert fat to carbohydrates (food)
Vacuoles
 Largest organelle
 As much as 90% of cell
 Can be one or two in cell
Vacuoles
 Vacuoles contain cell sap
 Proteins, sugars, etc
 Anthocyanins
 Provides color
 Red, blue or purple flowers
and some reddish foliage
 Vacuoles maintain cell
pressure
Cytoskeleton
 Cytoskeleton
maintains cell structure
 Microtubules
 Maintain structure
of cell wall
 Microfilaments
 Move material and
organelles inside
cell
 Cytoplasmic
streaming
 CELL
https://www.youtube
.com/watch?v=URUJ
D5NEXC8
CELLULAR REPRODUCTION
Cell Cycle
 All organisms begin life as a single cell
 Division begins almost immediately
Cell Cycle
 Interphase
 Living cells are not dividing
 Mitosis
 Four phases of cell division
Mitosis
Prophase
 Nuclear envelope fragments
 Chromosomes become shorter and thicker
 Contain the DNA
 Blueprint of the organism
Mitosis
Prophase
 Shorter and thicker chromosomes
transform into pairs
 Chromotids
 Pairs held like bowties
 Centromeres (knot)
 Technically, two knots together
 Dense protein complexes located
on outer surface of centromere
 Kinetochore
Mitosis
Prophase
 Microtubules develop at opposite poles of the cell
 Spindle fibers
 Attach to centromere
 Nuclear envelope has been completely fragmented
 Absorbed by the endoplasmic reticulum
Mitosis
Metaphase
 Pairs are lined up in the center of the cell
Mitosis
Anaphase
 Sister chromotids separate
 Two knots of centromere pull apart by spindles
 Moving to opposite poles of the cell
Mitosis
Telophase
 Nuclear envelope reforms around each set of chromosomes
 Cell plate forms between nuclei
 MITOSIS https://www.youtube.com/watch?v=4govZdjEBrs