Cell Bio Test Study Set

Phospholipid

Made up of a hydrophilic polar head, and two hydrophobic nonpolar tails.

Phospholipid Bilayer

What the cell membrane is made up of

How phospholipids arrange themselves

So the heads contact water inside and outside of the cell

How nonpolar hydrophobic barriers are formed

The tails are hidden in the middle of the cell

Transport proteins

Act as channels, gates, or pumps that allow materials into and out of the cell

Receptor proteins

Act as receptors for cell messengers such as hormones or changes in the enviornment

Marker proteins

Act as identification for the cell which is useful for cell sorting and the immune system

Passive transport

A process that moves molecules from a high to low concentration (P)

Does passive transport require energy?

No

What is passive transport based on?

Diffusion

What is diffusion?

Movement of molecules form a high to low concentration (D)

Is energy required in diffusion?

No

What does simple diffusion allow?

Small molecules like O2 and CO2 to pass through the membrane

When will the changes in concentration of a substance stop?

When they reach an equilibrium

What is an equilibrium?

When concentration of molecules are equivalent on both sides of the membrane

Selectively permeable

Not all molecules can pass through the membrane

When a membrane is selectively permeable, what molecules can and cannot pass through?

Can: nonpolar, small molecules

Cannot: large molecules

What is osmosis?

The diffusion of water

No

Does osmosis require energy?

Is osmosis a form of active or passive transport?

Passive transport

What is a hypotonic solution?

A less concentrated solution

Inside

In a hypotonic solution, is there a lower concentration of water inside or outside of the cell?

What happens when wawter enters the cell in a hypotonic solution?

The cell would enlarge and possibly burst

What is a hypertonic solution?

A very concentrated solution

Is there a higher concentration of water in the cell inside or outside of the cell?

Inside the cell

What happens when water leaves the cell in a hypertonic solution?

The cell shrinks

What is an isotonic solution?

A solution where the concentration of water is the same inside and outside of the cell

Why does a cell maintain its size as water enters in an isotonic solution?

Because water enters and leaves at the same rate as it's entering

Different methods

Do organisms use the same or different methods to prevent their cells from bursting?

How do plant cells protect themselves from bursting?

With a cell wall

How do unicellular organisms protect themselves from bursting?

They pump water out

How do animal cells protect themseles from bursting?

They surround themselves with an isotonic fluid (extracellular)

What happens in facilitated diffusion?

Proteins assist the diffusion process

Is facilitated diffusion a form of active or passive transport?

Passive transport

What does passive mean?

No energy

What does active mean?

Involves energy

What is active transport?

A process that moves molecules from a low-high concentration

Does active transport require energy?

Yes

What process does active transport typically refer to?

When cell membrane proteins act as pumps

What would happen if red blood cells were placed in a container of distilled water?

Expand and likely burst, because distilled water is a hypotonic solution

If two different cells were placed in a 0.8% salt solution, and one burst, and the other shrunk, what happened?

The cell that burst were in a hypotonic solution, and the cell that shrunk was in a hypertonic solution.

Why can a solution be hypotonic to one cell, but hypertonic to another?

It's all relative

What are the similarities between diffusion and osmosis?

They both transfer molecules until equilibrium, involves molecules moving over a membrane, both doesn't require energy

What is the difference between diffusion and osmosis?

Osmosis is strictly the diffusion of water

What is the similarity between facilitated diffusion and active transport?

They both move molecules througn the membrane

Facilitated diffusion: uses proteins, passive, high to low concentration

Active transport: uses energy, low to high concentration

What are the differences between facilitated diffusion and active transport?

What are the large scale forms of active transport?

Endocytosis and exocytosis

What is endocytosis?

The process where materials are taken into the cell by forming vesicles from the cell membrane.

What are vesicles?

Tiny vacuoles

What is phagocytosis?

A type of endocytosis where the cell membrane surrounds and absorbs large proteins

What is pinocytosis?

A type of endocytosis where the cell membrane surrounds droplets of liquid

What is exocytosis?

The reverse of endocytosis

Phagocytosis and pinocytosis are types of what form of active transport?

Endocytosis

What is the reverse of endocytosis?

Exocytosis

What does the cell theory state?

All living things are composed of cells and all cells come from other cells

What is the plasma/cell membrane?

Thin layer of lipids and proteins that acts as a selective barrier

What is a cell/plasma membrane mostly made of?

Phospholipid bilayer

What do prokaryotic cells lack?

A membrane enclosed nucleus and other organelles

What do prokaryotic cells consist entirely of?

Archaea and bacteria

What do eukaryotic cells have?

Membrane enclosed nuclei and other organelles

What is cytoplasm?

The inside portion of both prokaryotic and eukaryotic cells

What portion of the cell is cytoplasm?

The portion between the nucleus and the plasma/cell membrane in eukaryotic cells

Where does most of the business of the cell take place?

Cytoplasm

What is the nucleoid region?

A region of concentrated mass of DNA in prokaryotic cells

What is a cell wall?

The outermost layer of the cell, protective,outside the cell membrane that helps the cell maintain its shape

What is a capsule?

A sticky layer around the bacterial cell wall

What does a capsule do?

Protects the cell surface and sometimes helps glue the cell to surfaces

What is pili also known as?

Fimbriae

What is pili?

Short projections on the surface of prokaryotes

What do pili do?

Attach to other surfaces

What pili are used in conjugation?

Specialized sex pili

What is prokaryotic flagella?

A long surface projection

What does prokaryotic flagella do?

Moves a cell through liquid

Are eukaryotic and prokaryotic flagella the same?

No

What are organelles?

Small structures in the cell that are wrapped in a membrane made up of phospholipids and proteins

What does the nucleus contain?

DNA, and therefore the instructions for making proteins

What is chromatin?

Fibers that consist of nuclear's DNA attached to proteins

What are chromosomes?

Individual fibers of chromatin

What do chromosomes do?

Allow the cell to pass Dna to the next generation of cells

What is the nuclear envelope?

Two membranes that enclose the nucleus

Where are nuclear pores located?

On the nuclear envelope

What do nuclear pores do?

Allow small molecules through

What is the nucleolus?

A structure inside the nucleus

What does the nucleolus do?

Makes the building blocks of ribosomes

What are ribosomes?

Very small structures that make protein

What is the smooth endoplasmic reticulum?

A network of interconnected tubules

Why is the smooth ER called smooth?

It lacks ribosomes

What does the smooth ER do?

Makes lipids such as fatty acids, phospholipids, and steroids, and therefore makes cell membranes

What does the smooth ER in liver cells and other parts of the body do?

Detoxifies drugs and other harmful substances

What does the rough endoplasmic reticulum do?

Modifies, stores, and transports proteins

Where do proteins come from?

Made by ribosomes

What covers the rough ER's surface?

Ribosomes

What can the rough ER produce?

New membranes

What does the golgi apparatus do?

Collects, modifies, packages, and distributes proteins and other cell products that are shipped out of the cell or to other parts of the cell

Where did the proteins and products the golgi apparatus distributes originally come from?

Rough ER

What is the golgi apparatus made up of?

A series of unconnected sacs

What are lysosomes?

Small structures that contain enzymes and chemicals

What are the enzymes and chemicals in lysosomes neccesary for?

Digesting and recycling material in the cell

What are lysosomes formed by?

The rough ER and golgi apparatus

Animal

Are lysosomes in plant cells, animal cells, both, or neither?