REMEMBER! CELLS ARE THE INDIVIDUAL LIVING UNITS THAT MAKE UP ALL LIVING ORGANISMS.
MULTICELLULAR: Made of 2 or more cells UNICELLULAR: Made of just one cell MICRO-ORGANISMS : Very small, generally unicellular organisms that can be seen only through a microscope
Unicellular organisms :developed specialized structures to perform functions such as eating, moving, reproducing, excreting and reacting to stimuli. (Bacteria, amoebas, paramecium)
Multi-cellular organisms: rely on many very specialized cells to perform functions such as to eat, to move, to reproduce, all the cells interact with one another. (
Ex. To eat: cells for digestion, cells for absorption, cells for carrying nutrients throughout body, cells for the muscle to move
ROTIFERS ARE THE SMALLEST KNOWN MULTICELLULAR ORGANISM
AMOEBA
Lives in water, Moves around using pseudopodia
Foot-like projections. ‘False feet’
A pseudopod is extended and the cytoplasm fills it. Moves very slow
Also uses the pseudopodia to eat by surrounding their food (algae, bacteria, plant cells) to create a vacuole
PARAMECIUM
Moves very fast in the fresh water, covered in cilia to move
Hair like structures that move back & forth
Cilia also used to capture food (algae) by channeling food to an oral groove
Forms a food vacuole to be digested
Cell Structures
ORGANELLES: Inside the cell, there are structures that have particular functions to keep the cell alive
Some organelles may be found in both plants and animals
Some may only be found in plant cells
Some may only be found in animal cells
Why the variety of organelles? Depends on the purpose of the cell (Ex. Muscle cell vs. leaf cell)
Organelles
NUCLEUS: The command center of the cell
Control’s the cells activities
Holds the cell's DNA
Directs all cellular activities such as movement, growth, and other life functions
In both plants and animal cells
MITOCHONDRIA: The powerhouse of the cell
Chemical reactions occur that convert energy into useable forms
In both plant cells & animal cells
CELL MEMBRANE: Controllable gateway in and out of the cell
Surrounds & protects the contents of the cell
Looks like a thick line around the cell
Lets needed materials in & waste materials out
In both plant cells & animal cells
VACUOLES: The storage room of the cell
Membrane bound sac acting as a storage space for excess food & wastes
Clear, liquid filled space in cytoplasm
Plants generally have 1 big vacuole, animal cells generally have many small vacuoles
CYTOPLASM: The Kitchen of the cell
Covers everything inside the cell except the nucleus
Contains nutrients required by the cell
Distributes material to different parts of the cell
Found in both plant cells & animal cells
LYSOSOME:The trash can of the cell
break down worn out parts of the cell
depending on the type of cell are used to kill bacteria or viruses
Structures only found in Plant Cells
CELL WALL: The frame of the cell
Found in Plant cells NOT in animal cells
A rigid frame-like covering that surrounds the cell membrane
Provides support for the cell
CHLOROPLASTS: The solar panels of the cell
Structures in which photosynthesis takes place
Greenish structures found only in plant cells
How Substances Move Into and Out of Cells
DIFFUSION: Movement of particles of a substance from an area of higher concentration to an area of lower concentration
It’s a balancing out process of the particles where No energy required
DIFFUSION OF PARTICLES MOVE FROM AN AREA OF HIGH CONCENTRATION TO LOW
OSMOSIS:
Special kind of diffusion
Diffusion of water through a selectively permeable membrane
Water particles are small enough to diffuse through the cell membrane with ease, depending on the concentration gradient (L to H)
Osmosis is vital to the survival and health of cells
SELECTIVELY PERMEABLE: A membrane with very small openings that allow particles of some substances, but not others, to pass through. (Based on size)
A permeable membrane allows all materials to go in & out
An impermeable membrane does not allow anything in or out.
DIFFUSION & THE CELL MEMBRANE PARTICLES OF MANY SUBSTANCES MOVE IN & OUT OF CELLS BY DIFFUSION
However, the cell membrane acts like a filter with its tiny openings, allowing some particles to go through if they are small enough (I.e. semi-permeable!)
THREE TYPES OF WATER SOLUTIONS ISOTONIC SOLUTION: Equal concentration of solutes on each side of semi-permeable membrane
HYPERTONIC SOLUTION: Solution with high concentration of solutes (very concentrated)
Water leaves the cell, and it shrivels
Potentially fatal
HYPOTONIC SOLUTION: Solution with the lower concentration of solutes
Water enters the cell, and the cell swells
Potentially fatal
Cells need an optimal amount of water concentration. There needs to be a balance inside & outside of the cell. If too much water enters and/or leaves the cell, the cell may die