Transcript Cell Structure & Function

Life is Cellular
SPI.1.1 Identify the cellular organelles
associated with major cell processes.
SPI.1.2 Distinguish between prokaryotic and
eukaryotic cells.
The Cell Theory
• All living things are composed of cells
• Cells are the basic units of structure
& function in living things
• New cells are produced from existing
cells
Prokaryotic Vs. Eukaryotic
• Prokaryotic
– No Nucleus
– No
Membrane
Covered
Organelles
– Circular DNA
• Eukaryotic
–Nucleus
–Membrane
covered
organelles
–Linear DNA
Prokaryotic Cell
Eukaryotic Cell
Two Types of Eukaryotic Cells
• Animal
–Cell
membrane
–Mitochondria
–Small to no
vacuole
• Plant
–Cell wall &
membrane
–Chloroplast &
Mitochondria
–Large Vacuole
Eukaryotic Components
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Cell Membrane (& Cell Wall)
Nucleus
Ribosomes
Endoplasmic Reticulum
Mitochondria (& Chloroplast)
Golgi Complex
Vesicle
Vacuole
Lysosome
Cell Membrane
• Made of phospholipids
–Hydrophobic vs. Hydrophilic
Cell Membrane
• Functions:
–Keep in cytoplasm
–Allow in nutrients
–Excrete waste
Cell Wall
• Found in plants and algae
• Made of cellulose
–Carb
Cell Wall
• Functions
–Strength
–Support
• Prevents the
tearing of the
cell membrane
Nucleus
• Functions:
–Control center
–Stores genetic info
–Instructs protein synthesis
• Contains DNA
• Contains Nucleolus
–Make ribosomes
Ribosomes
• Makes proteins
–Proteins = amino acids
• Smallest organelle
• No membrane
–Made of RNA
Cytoskeleton
• Network of filaments & tubes that
cross in the cytosol
• Functions
–Give shape (tent)
–Tracks to move items
Endoplasmic Reticulum
• AKA – ER
• Functions as the
intracellular highway
• Two types
–Rough ER
–Smooth ER
Rough ER
• Flattened sacs covered with ribosomes
• Produces:
–Phospholipids
–Proteins
• Most abundant:
–Digestive
–Antibody producing
Smooth ER
• No ribosomes on surface
• Less than rough ER
• Functions
–Produces estrogen & testosterone
–Detoxifies in liver & kidney
Chloroplast
• Plants and algae
• Contains chlorophyll
–Traps sunlight
• Performs photosynthesis
Mitochondria
• Where most of the ATP is produced
–Produced in the inner membrane
–ATP= energy
–Needs oxygen
Endosymbiotic Theory
• Mitochondria & chloroplast originated from a
symbiotic relationship b/t prokaryotic &
eukaryotic cells
• Prokaryotic cells
–Mitochondria = aerobic bacteria
–Chloroplast = cyanobacteria
Endosymbiotic Theory
• Evidence
–Own DNA
–Double membrane
–Binary Fission (independent)
–Size
–Own ribosomes
Golgi Apparatus
• Process and ships out proteins & other
materials out of the cell
• Close to cell membrane
• Modify the ER products
–Add carb labels =
direction to other cells
Lysosomes
• Special vesicles that contain
enzymes
• Originate from Golgi
• Functions
–Break down carbs, lipids, & proteins
from food
–Destroy worn out organelles
–Rid cell of waste
Vacuoles
• Store water for the cell
• Large in plant cells
–Supports the cell
• Wilting
Movement Through
Membranes
SPI.1.7 Predict the movement of water
and other molecules across selectively
permeable membranes.
SPI.1.8 Compare and contrast active and
passive transport
Cell Membrane
• Lipid Bilayer
–phospholipids
• Protein channels
–Allows molecules to
pass
• Carbohydrate chains
–Cell to cell recognition
Selectively Permeable
• Selective = picky
• Permeable = allows things to pass
through
Selectively Permeable
Solutions
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A homogenous mixture in a liquid form
Mixture = solute + solvent
Solute – dissolved particles
Solvent – dissolving liquid
–Usually water
• Solutions are formed by diffusion
Solutions
Solvent
Solutes
Solution
The Formation of a SugarWater Solution
Concentrations
__Mass of Solute__ Concentration of
=
Solution
Volume of Solution
Example: If you dissolve 12 grams
of salt in 3 liters of water, what is
the concentration?
4 g/L
Movement Across
Membranes
• Passive – NO energy required
– Diffusion
– Osmosis
– Facilitated diffusion
– Ion Channels
• Active – Energy Required
– Pumps
– Endocytosis
– Exocytosis
Diffusion
• Movement of particles across
membranes
• Move by concentration gradient
• High conc.  Low conc.
• No energy required
• Goal = Equilibrium
• Rate determined by steepness of
gradient
Diffusion Demonstration
• Dialysis tubing = selectively
permeable membrane
• Phenolthalien - Indicator
– Base – pink
• Iodine – indicator
–Starch - black
Osmosis
• The diffusion of water across a membrane
• Movement determined by solute
concentrations
– Hypotonic
– Hypertonic
– Isotonic
Hypotonic Solutions
• LOWER concentration of solutes
Hypertonic Solutions
• HIGHER concentration of solutes
Isotonic Solutions
• Equal concentrations of solutes
Water Movement (Osmosis)
–Water moves from hypotonic to
hypertonic solution
–Isotonic water moves both ways
Effects of Osmosis
Osmosis in Blood Cells
Facilitated Diffusion
• Movement of specific molecules
across the cell membrane by protein
channels
• No energy required
• Moved by concentration
gradients
• Ex: Glucose
Active Transport
• Movement of particles through proteins
against the normal direction of diffusion
• Lower conc.  higher conc.
Ion Pumps
• Similar to channels but move AGAINST the conc. gradient
• Na-/K+ pumps
– 3 Na- ions (inside) bind to carrier protein
– ATP opens protein by changing channel shape
– Na- released to outside and 2 K+ (outside) bind
– Protein resumes its original shape – releasing K+
into cell
Endocytosis
• Cells surround a particle and
encloses it in a vesicle to bring it into
the cell
Exocytosis
• Vesicles formed in the ER or Golgi
complex carry particles out of the cell by
fusing membranes
Organization of Life
Chapter 7
Section 4
Unicellular Organisms
• Single celled organism
• Prokaryotes
–Bacteria
• Eukaryotes
–Yeast
• Colonial
–Volvox
Multicellular Organisms
• Organisms composed of many cells
• Cells work as groups for specialized
functions
Specialized Cells
• They will have specialized functions
• Examples
–Bone
–Blood
–Skin
Organization
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Cell
Tissues
Organs
Organ Systems
Organism
Tissues
• Examples
Organs
• Animal
–Stomach
• Plants
–Roots
Organ Systems
• Failure of one part can affect the
others in the system
• Digestive
Organism
• Unicellular
• Multicellular
After Organisms?
• Populations
• Communities
• Ecosystem