Diversity of cellular life

What are unicellular organisms.

Examples

Single celled organism

Bacteria yeast amoeba paramecia

What are colonial organisms

Why aren’t they considered multicellular

Group of genetically identical cells that live in a connected group

They are not considered multicellular bc there is little coordination. There is so cell specialization or differentiation

What does a multicellular organism consist of

Groups of specialized cells that live and work together

in multicellular organisms there is a very high level of….

Differentiation, cell specialization and coordination of cellular activity

What is cell specialization

The evolutionary adaptation of a cell or group of cells to carry out one particular function

what is an advantage of cell specialization

A cell that carries out only one function can be much more efficient at that one job

What is a disadvantage of cell specialization

The cells are dependent upon one another. If one group of cells fails to do its job the other cells will perish

What are the levels are cellular organization

(Give description of each)

Cats take over streets

1. Cell: Smallest unit that carries all processes of life

2. Tissue: group of similar cells that carry out specific function

3. Organ: Group of tissue functions as a unit performing same function

4. Organ system: Groups of organs they work together to carry out related tasks

Various organ systems work together = multicellular organisms

Whats another name for cell membrane

Plasma membrane

What are the parts of a membrane

Pretty-boys cant take carbs particularly pasta

Phospholipid bilayer,

Transport proteins

proteins,

carbohydrates,

cholesterol

Phospholipid

A: Phospholipid bilayer

B: Protein

C: Transport proteins

D: Phospholipid

E: Cholesterol

F: Carbohydrate

What does the cell membrane regulate and provide

Regulates what enters and exits the cell

Provides protection and support to the cell

What does the cell membrane consist of?

What are the structural components of membranes?

Phospholipid bilayer (double layer) which proteins are embedded

Phospholipids

What kind of structure does a lipid bilayer give the membrane

A flexible structure that forms a strong barrier between the inside and outside of cell

What are the different types of proteins embedded within phospholipid bilayer

TRE

Transport proteins

Receptor proteins

Enzymes

What are transport proteins

They form channels and pumps to help move materials across membrane

What are receptor proteins

they recognize and bind to substances at the cell surface forming a method of communication between the cell and the external environment

What do carbohydrates serve as

They act as identification markers to help individual cells identify one another

What is the term fluid mosaic used to describe

The nature of membranes in cells

Does the phospholipid bilayer act more as a liquid or solid

Acts more like a liquid

The lipids and proteins in the membrane move laterally within the bilayer

Because of the constant movement in the bilayer what can we say about the lipids and proteins

That they are constantly changing = Fluid mosaic

Why must a cell closely regulate the water content of the cell

B/c if too much water will rupture and die, too little will shrivel and die

Maintaining homeostasis requires what

Self regulation of materials coming into the cell and going out of the cell

Is a cell an open or closed system + why

Open system bc it requires the constant inflow of energy and matter and constant outflow of waste

The cell membrane is called a…

Selectively permeable membrane or a semipermeable membrane W

What does selectively permeable mean (In terms of cell membrane)

It has the ability to let some substances pass through more easily than others, some materials aren’t allowed to enter at all.

also control the speed at which molecules are allowed to enter

They cytoplasm of a cell contains what?

Contains a solution of many different substances in water and these substances exist in various concentrations

The outside of a cell is surrounded by what

By different water solutions containing different concentrations of the same or different substance

What is the concentration gradient

Its the difference in concentration of molecules across a distance.

In the absence of forces materials will tend to move from an area of high concentration to an area of lower concentration

In the absence of forces materials will tend to move from an area of ______ concentration to an area of ______ concentration

high, lower

Label the area of high concentration, label the area of lower concentration, draw an arrow on the drawing showing the direction of movement in this solute

Describe whats happening in this drawing

A: Higher concentration of solute molecules on one side of the membrane

B: The molecules move from the side of higher concentration to the side of lower concentration. This movement will continue until the concentration is equal on both sides

C: Equilibrium has been reached. The concentration is equal on both sides of the membrane. Once equilibrium has been reached, the solute molecules will continue moving in both directions

The movement of molecules across a membrane may or may not require an expenditure of ________

What are the two ways molecules are moved into and out of cells

Passive transport

Active transport

What are the types of passive transport

POD

Passive transport

Diffusion

Osmosis

What is passive transport

The movement of substances across the cell membrane without use of energy

What is diffusion

Diffusion is the spreading out of molecules from a region of high [ ] to a region of low [ ]W

What determines wether a molecule can diffuse across the cell membrane

The size and type (Polarity)

What molecules can diffuse directly through the phospholipid bilayer / why

Small non polar molecules can (O2, CO2) = Bc they are small and non polar so they dissolve through the phospholipid bilayer

How do polar molecules cross the cell membrane + examples

They move through protein channels or by the use of transport proteins

(Water ions proteins)

What is osmosis / is cell energy required

The movement of water across membrane from region of high concentration to region of low concentration.

Osmosis = passive transport of water no cell energy required

What determines the net direction of osmosis

The relative [ ] of solutes on two sides of the membrane

What are the three types of water solution

Isotonic, Hypertonic, hypotonic

What is an isotonic solution

The concentration of solutes outside and inside the cell are equal

The [ ] of water is the same on the inside and the outside of the cell

Water will flow back and forth across the membrane but at the same rate and in both directions

What is a hypertonic solution

[ ]of solute molecules is higher than the [ ] of solutes inside the cell

Water will diffuse out of the cell until equilibrium is reached.

Plasmolysis may occur

What is plasmolysis

Too much water moves out and the cell wall collapses

What is a hypertonic solution

[ ]of solute molecules is lower than the [ ] of solutes inside the cell.

Water diffuses into he cell until equilibrium is reached

Cytolysis may occur

What is cytolysis

Too much water moves into cell and cell membrane ruptures bc of water pressure

Water moves from the ________ side to the _______ side

Hypotonic , Hypertonic

What is facilitated diffusion

Type of passive transport used for molecules that do not readily diffuse through membranes.

Why do some molecules require facilitated diffusion

bc they cannot readily diffuse through the phospholipid bilayer

What types of molecules use facilitated diffusion

Polar molecules (water, glucose)

Large molecules that are too big to pass through membrane

How do molecules move across the membrane during facilitated diffusion

They move through transport proteins or protein channels in the membrane

Does facilitated diffusion require energy

No form of passive transport

Why is it called facilitated diffusion

Bc transport proteins help facilitate molecules diffuse across the cell membrane

Why is facilitaed diffusion considered passive transport

Bc molecules move down their concentration gradient (High to low) and no energy is required

How to transport proteins help in facilitated diffusion

They provide a passage way through the membrane allowing molecules to cross more quick

When is active transport needed

When materials must move against concentration gradient (Low to high [ ])

What is the active transport

The movement of substances from low concentration to high concentration requiring energy

How small are molecules and ions moved during active transport

By transport proteins embedded in cell membrane

Do protein pumps require energy

Yes. protein pumps use ATP to move substances against their concentration gradient

How are large molecules transported across the cell membrane

By endocytosis and exocytosis

What is the difference between passive transport and active transport

Passive

• No ATP

• High to low [ ]

• Includes diffusion, osmosis and facilitated osmosis

Active

• Requires ATP

• Low to high [ ]

• Includes protein pumps, endocytosis and exocytosis

What is endocytosis

Process of bringing materials into the cell by the cell membrane folding inward to form a vesicle

How does endocytosis work

The cell membrane folds inwards forming a pocket

Pocket pinches off

A vesicle forms inside the cytoplasm containing material

What kind of materials are taken into the cell by endocytosis

Large molecules and food particles

Does endocytosis require energy

Yes. Endocytosis = form of active transport (ATP)

What are the two types of endocytosis

Phagocytosis

Pinocytosis

What is phagocytosis

The engulfing of large food particle by the cell

What is pinocytosis

Cell drinking. The cell engulfs droplets of extracellular fluid to obtain the dissolved molecules

During pinocytosis what does the cell actually need

The molecules dissolved in the fluid not the fluid itself

What is exocytosis

Process of releasing large materials out of the cell

How does exocytosis work

A vesicle fuses with the cell membrane releasing its contents outside the cell