Cell Structure and Function

Cell Theory (3)

all living things are made of cells, cells come from pre-existing cells, cells are the basic unit of structure/organization of life

What are the two types of cells ?

Prokaryotic and Eukaryotic

Prokaryotic cells (5)

no nucleus

small and simple cells

single celled

includes bacteria and archaea

no membrane bound organelles

Eukaryotic cells (6)

have nucleus.

larger and more complex cells.

single celled or multicellular

includes: plants and animals and fungi and protists.

all of domain eukarya.

membrane bound organelles

What are 4 things that only prokaryotic cells have (CPPN)

capsules (a sticky outer coat), pili (short projections, plasmids (small rings of DNA), nucleoid coiled DNA (no membrane)

The cell wall surrounding plasma membrane is made of a combination of what

starch and protein (called peptidoglycan)

What are 4 things that are all eukaryotes (FAPP)

fungi, animals, plants, protists

What do all eukaryotic cells have (5)

plasma membrane, cytoplasm, nucleus, ribosomes, mitochondria

Lysosomes only appear in which cell

animal cells

What 3 things do plant cells have

chloroplasts, cell walls, central vacuoles

Lysosome (3 things)

a membrane-enclosed bubble of digestive enzymes that can break down and recycle foreign or worn-out cellular substances. a vesicle specialized for digestion. contains acidic environment and digestive enzymes to break down waste within the cell, like damaged cellular machinery or anything the cell has eaten that needs to be destroyed

Plasma Membrane

phospholipid bilayer surrounding cell that is embedded with proteins, starches, cholesterol. it separates cellular contents from outside world and regulates passage of material into and out of the cell. it is composed of phospholipids

Cytoplasm (2 things)

Jelly like substance that fills up the interior of the cell.

all organelles are suspended in cytoplasm and are held in place by cytoskeleton.

Cytoplasm fluid

cytosol, which is mostly water with dissolved sugars and proteins

Cytoskeleton (4 things)

"cell skeleton."

consists of protein filaments and fibers which give structure and support to cells.

moves substances around the cell and acts like a public transportation system.

forms flagella and cilia so cells can move

Endomembrane System. what does it do (4) and what does it include (6)

works to coordinate production, modification, packaging, and transportation of proteins and lipids.

includes nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, vesicles, and plasma membrane

Nucleus (4 things)

contains DNA which in eukaryotes is in linear pieces called chromosomes. produces ribosomes at the nucleolus. surrounded by double layer membrane called nuclear envelope. DNA directs functions of other organelles

Ribosomes (4 things)

organelles that build proteins. not made of membranes. found in all cells. in eukaryotes, ribosomes are both attached to the endoplasmic reticulum and free floating in the cytoplasm

Endoplasmic Reticulum (2 things)

folds of membranes surrounds nucleus. interior spaces contain proteins and other enzymes that carry out crucial functions

What are the 2 types of endoplasmic reticulum

rough ER (has ribosomes), and smooth ER

Rough endoplasmic reticulum (2 things)

proteins are produced and folded within rough ER. mostly produces proteins that will be secreted from the cell

Smooth endoplasmic reticulum (4 things)

no ribosomes. produces fats, steroids, carbs, and phospholipids. detoxifies medications, alcohol, poisons. stores calcium

Golgi Apparatus (2 things)

Sorts and ships products produced by the ER. makes some final modifications before product is sent to its final destination

Peroxisomes (4 things)

cousins of lysosomes. break down fatty acids and amino acids. breaks down toxic materials and produces hydrogen peroxide as a by-product. detoxifies alcohol, poisons, any substances that may be harmful

Bacteria-like organelles (4 things)

two organelles found within eukaryotic organisms were once free-living bacteria. were brought into the cell but not destroyed. instead lived on as machinery within the cell. function in converting energy from one form to another

Endosymbiosis

inside together life

Chloroplasts and Mitochondria

have DNA that is unique from nuclear DNA. make their own ribosomes and has a double membrane

Mitochondria (3 things)

found in all eukaryotic cells, including plants and algae. convert chemical energy, mostly sugars, into usable form (adenosine triphosphate, ATP). provides energy to keep the cell functioning

What are the usual shapes of a plant cell vs an animal cell

plant cells tend to be rectangular, animal cells tend to be amorphous (circle)

Chloroplast (4 things)

contains structures that convert light energy into food energy during the process of photosynthesis. found in plant and algae cells. pigment chlorophyll converts solar energy to chemical energy (photosynthesis). allow organisms to "feed themselves" (autotrophs).

Cell wall

a rigid, protective layer made of cellulose that helps maintain cell shape

central vacuole

a storage sac that can hold a variety of substances, such as nutrients or water

Plant cell wall (2 things)

rigid structure made of cellulose. provides structure and support for plant cell

Large central vacuole (3 things)

large vesicles. provides pressure pushing out on the cell - turgidity. stores water and other substances

Cell membrane

composed of phospholipids, which have a head and two long legs. the split personality of phospholipids makes them good membrane material

Hydrophilic head (2 things)

consists of a molecule of glycerol linked to a molecule containing phosphorous. this region is said to be "polar" because it has an electrical charge.

Hydrophobic tail (4 things)

the fatty acid tails of the phospholipid are long chains of carbon and hydrogen atoms.

have no electrical charge.

the carbon-hydrogen chains are non-polar molecules.

molecules that do not mix with water are said to be hydrophobic

How is a plasma membrane arranged

two sheets of phospholipids are arranged so that the hydrophobic tails are all in contact with each other and the hydrophilic heads are in contact with the watery solution both outside and inside the cell creating the phospholipid bilayer

Anything spanning the membrane must also follow what

the properties of the phospholipid bilayer

Receptor Proteins

bind to chemicals in the cell's external environment and, by doing so, regulate certain processes within the cell

Recognition proteins (2 things)

makes it possible for the body's immune system to distinguish the cells that belong inside you from those that are invaders and need to be attacked. recognition proteins also can help cells to bind to adhere to other cells or molecules

Transport proteins (2 things)

help large and/or strong charged molecules to pass through the membrane. transport proteins come in a variety of shapes and sizes, making it possible for a wide variety of molecules to be transported

Enzymatic proteins (3 things)

accelerate chemical reactions on the cell membrane's surface. a variety of different enzymatic proteins exist. some accelerate intracellular reactions and others accelerate extracellular reactions

every membrane is... (3 things)

selectively permeable. some substances flow freely and others pass under certain circumstances. some cannot pass

what do cells need to exchange across the membrane (4)

food, oxygen, carbon dioxide, waste

What molecules can pass directly through

small uncharged molecules like oxygen and carbon dioxide

What molecules cannot pass directly through and must be transported through using proteins

large or charged molecules like sugars, carbs, proteins, and water

What are the 3 types of transport across the membrane

passive, active, bulk

Passive transport (3 things)

requires no energy.

substances move along a concentration gradient from high to low.

simple diffusion, facilitated diffusion, osmosis

Active transport (6 things)

requires energy.

substances move against a concentration gradient from low to high.

ATP driven (like the sodium potassium pump.

molecules can't always move spontaneously and effortlessly in and out of cells.
necessary if the molecules to be moved are very large or if they are being moved against their concentration gradient.

important for contraction of muscles, nervous system, and maintaining homeostasis (normal cell processes)

bulk transport

endocytosis and exocytosis

When does diffusion occur

when a particle called a solute is dissolved in a gas or liquid (called a solvent) and moves from an area of high solute concentration to an area of lower concentration

When certain molecules are highly concentrated what happens

they keep bumping into each other and eventually end up evenly distributed. for this reason we say that molecules tend to move down their concentration gradient

Passive transport (simple diffusion) (2 things)

molecules move from areas of high concentration to low concentration. oxygen, carbon dioxide, and most lipids enter and leave the cell by simple diffusion

Passive transport (facilitated diffusion) (2 things)

large polar molecules like, glucose and amino acids, and ions, like sodium and chloride, cannot simply diffuse across the bilayer.

these molecules must pass through protein channels/transport proteins that facilitate diffusion across the membrane

Passive transport (osmosis) (2 things)

the diffusion of water. water will always flow from an area of higher water concentration to an area of lower water concentration

tonicity

when a cell is in a solution, we describe the concentration of solutes outside of the cell relative to inside the cell as the tonicity of the solution. think about the solute concentration in the fluid surrounding the cell

Hypertonic solution

has a greater concentration of solutes than the solution inside the cell (less water)

hypotonic solution

has a lower solute concentration than the solution inside the cell (more water)

Isotonic solution

concentration of solutes is the same inside and outside of the cell (same water concentration)

Crenated

wrinkled

exocytosis (2 things)

export from the cell. cells use vesicles containing waste products or material to be secreted to send out large amounts of material.

endocytosis

import into the cell

phagocytosis

takes in larger substances such as food or bacteria. "eating."

Pinocytosis

takes in fluids and solutes. "drinking"

Receptor Mediated Endocytosis

process by which cells absorb molecules by using receptor proteins

If you are presented with a tube or a glass that has glucose, sodium, and water, how many solutes are in that solution

2

If you are shown a diagram that has a glucose solution and it is placed in a beaker of water and the bag is semi-permeable where do you expect the water to move ?

inside

Was the starch inside or outside ?

inside

Will the bag get bigger, shrink, or stay the same ?

bigger

If you have that same solution, the distilled water is hypertonic or hypotonic to the solution in the bag ?

Where does the glucose move ? does it move outside or inside the bag ?

you are shown a diagram of diffusion across a semipermeable membrane. where is the salt going to diffuse ?

high concentration to low concentration

If you were to be shown two substances being diffused across something, the substance that is larger will always...

diffuse faster

If something diffuses through a medium, there will be...

more of it spread throughout that medium, it will be more pigmented in color.

when you have more concentration of something, the diffusion rate will be...

generally more faster

The higher the concentration of something...

the more rapidly the chemicals will diffuse