Chapter 4 Bio

capsule

(sticky outer coat) that surrounds the cell wall help glue prokaryotes to surfaces, such as sticks and rocks in streams

flagellum

A long, whip-like structure that protrudes from the cell's surface to help it move Generally less numerous than cilia e.x. most animals have flagellated sperm longer than a cilia, flagellum are how the cell moves unicellular = has this to move to food

cytoskeleton

A meshwork of protein fibers that extend throughout the cytoplasm of a cell, providing structural support and involved in different types of cell movement

Smooth ER

Has enzymes embedded in its membrane Has no ribosomes on its surface

Rough ER

Has ribosomes studded on its surface

Eukaryotes

Have a nucleus Have membrane-bound organelles Have subcellular structures called organelles (well-defined, intracellular bodies that perform specific functions for the cell) Protists, Fungi, Plants, and Animals are composed of these

golgi apparatus

Receives and chemically modifies substances manufactured by the Rough ER One function of chemical modification is to mark and sort molecules into different batches for different destinations like a warehouse putting on a barcode (taking things in modifying them and sorting them so they can go to specific parts of the cell) -2 sides (one where things go in, one where things go out)

cilia

Short, numerous locomotor appendages -very short, come out in bunches (not by themselves) -found in a person's trachea -as you breath in, they catche and trap the dirt -coughing = lungs are disposing of the dirt and dust

cytoplasm

The interior of the cell that is fluid-filled (watery/gely) and is the region between the nucleus and the plasma membrane Also includes the cytoskeleton and all of the organelles except for the nucleus

tight junctions

bind cells very tightly together, forming a leakproof sheet

microtubules

both cilia and flagella are composted of these wrapped in an extension of the plasma membrane the thickest type of fiber Straight hollow tubes made of the globular protein tubulin Provide anchorage for organelles Act as tracks ("highway system") for organelle movement within the cytoplasm, or the transportation of information from the nucleus to other parts of the cell

periheral proteins

in the plasma membrane, more for structure

nuclear envelope

is a double membrane that separates the nucleus from the cytoplasm

nucleoplasm

jelly-like liquid that fills the nucleular region

flagella

longer projections that propel the prokaryotic cell through its liquid environment

intermediate filaments

medium-sized Made of fibrous proteins Ropelike structure Reinforce cell shape and anchor certain organelles (e.x. hold nucleus, endoplasmic, microchondria all anchored in place)

glycoproteins

most animal cells secrete and are embedded in a sticky layer of (the extracellular matrix)

central vacuole, chloroplasts, cell wall

not in animal cells

anchoring junctions

rivet cells together with cytoskeletal fibers, forming strong sheets

pili

short projections that help prokaryotes attach to surfaces

vesicles

small, membrane-bound sacs that transport substances in cells (in golgi and a lysosome is an ex of one)

sterol

steroid based alcohols (a type of lipid that are in between the tails in an eukaryotic cell membrane)

fluid mosaic model

the cell membrane is called this because it acts like a liquid more than a solid, so the lipids and proteins can move laterally within the bilayer, like a boat on an ocean. This movement causes the pattern of the proteins and lipids in the cell membrane to constantly change also because it's made up of many different pieces (phospholipids, proteins, cholesterol)

nucleolus

the dense, central region of the nucleus where building blocks of ribosomes are produced and then exit the nucleus via the pores

mitochondrial matrix

the fluid in the inner membrane in mitochondria

cristae

the folds in the inner membrane of mitochondria embedded with enzymes that make ATP

cholesterol

the major sterol in the cell membrane of animal cells

basal body

the microtubule assembly extends in to this anchoring structure has the pattern of 9 microtubule triplets

cytosol

the part of the cytoplasm that includes molecules and small particles, such as ribosomes, but not membrane-bound organelles

Microfilaments

the thinnest type of fiber AKA actin filaments, as they are solid rods made mainly of the globular (globe-like) protein actin Arranged in a twisted double chain Help support the cell's shape Interact with other kinds of protein filaments to make cells contract

Endoplasmic Reticulum (ER)

touches the nucleus An extensive network of flattened sacs and tubes The membranes that form rough and smooth are continuous; membranes of the rough are continuous with the nuclear envelope as well

protein synthesis

1. Ribosomes synthesize polypeptides and then pass them into the rough ER where they are folded into their specific 3-D shape 2. Short chains of sugar are often linked to the polypeptide, making the molecule a glycoprotein 3. When the molecule is ready for export from the ER, the ER packages it in a transport vesicle 4. The protein now travels to the Golgi Apparatus for further processing 5. Finally, a transport vesicle containing the finished molecule makes its way to the plasma membrane to release its contents from the cell, but some vesicles ( e.x. containing needed enzymes) stay in the cell.

nucleus functions

Control region of the eukaryotic cell, as it contains the genetic material (DNA) which directs protein synthesis Following instructions in DNA, the part of the cell synthesizes RNA

cromatin

DNA is attached to proteins, forming long fibers DNA is in the form of this when the cell is not dividing relaxed form of a cromosome (what DNA looks like when your cell is at rest)

cell wall

Helps support and maintain the shape of the cell (provides the skeletal support that keeps plants upright on land) Protects the cell from damage Typically 10-100x thicker than the plasma membrane Consists of cellulose embedded in a matrix of other polysaccharides and proteins Rigid molecules called lignin, strengthen the cell walls of many plants (these strong cell walls are the main component of wood) cellulose polysaccharide

Rough ER Functions

Helps transport proteins that are made by its ribosomes Makes more membrane (some of the proteins made by its attached ribosomes are inserted into the membrane) which enlarges and then some is transported to other organelles Modifies proteins that will be transported to other organelles or secreted by the cell

prokaryotes

Lack a membrane-bound nucleus Lack membrane-bound organelles Their DNA is often concentrated in a part of the cell called the nucleoid region Divided into the domains of Bacteria and Archaea generally about 1/10 the size of the other type of cell

lysosome digestive functions

Many protists engulf food into food vacuoles, which lysosomes fuse with and break down the food, releasing nutrients to the cell Our white blood cells ingest bacteria into vacuoles, which lysosome enzymes rupture Lysosomes fuse with damaged organelles, etc. and dismantle their contents, allowing organic molecules to be re-available for use

Central Vacuole

Membrane-bound space that takes up much of the plant cell's volume Stores water and other substances, such as chemicals, nutrients and wastes When full, the cell is rigid (allows plants to stand upright) this part of flower petals may contain pigments that attract pollinating insects Some contain poisons to protect against plant-eating animals

Mitochondria

Organelles that carry out cellular respiration, converting the chemical energy of foods into ATP Highly active cells have hundreds of mitochondria (e.x. muscle cells) Nickname: "Power House of the Cell" metabolic pathway to provide energy -increase in # when cells must do a lot of work Consists of an outer and inner membrane The inner membrane contains the mitochondrial matrix, and cristae

Smooth ER Functions

Performs many different functions, including making lipids, including fatty acids, phospholipids, and steroids Breaks down toxins (with help from enzymes) How could this be linked to "tolerance"? When a nerve signal stimulates a muscle cell, calcium ions leak from the smooth ER (which stores smooth ER) into the cytoplasmic fluid where they trigger contraction of the cell

Common characteristics of cells

Plasma membrane (outer boundary; also referred to as cell membrane) Genes made up of DNA as hereditary material Ribosomes (tiny structures that make protein)

lysosomes

Spherical membranous organelles that contain digestive enzymes (help break things down) Demonstrates that the cell is truly compartmentalized, as they contain an acidic environment different and isolated from the rest of the cytoplasm -going to contain digestive enzymes Nickname: "Garbage Disposal" needs to be in this special organelle (if ruptured, the digestive enzymes with break and eat the cell down) type of vesicle

grana

Stacks of thylakoids where chlorophyll (a pigment) actually traps solar energy

cell/plasma membrane or phospholipid bilayer

The cell's outer boundary Covers a cell's surface and acts as barrier between the inside and outside of a cell Nickname: "Bouncer" or "Gatekeeper" primarily made up of two layers of phospholipids Has polar (hydrophilic) phosphate heads and nonpolar (hydrophobic) fatty acid tails. Heads point toward the water, tails away (inward) in both prokaryotic and eukaryotic cells

chloroplasts

Where photosynthesis occurs Use light energy to make carbohydrates from CO2 and H2O Along with mitochondria, these organelles help supply much of the energy needed to power the plant cell's activities Contain some DNA and ribosomes and make some of their own proteins

ribosomes

Where proteins are made Found in the cytoplasm or on the Rough ER Small, roughly spherical Made up of a large and a small subunit Made of protein and RNA RNA messenger (has a code that is sent to the tRNA)

9+2 pattern

a ring of 9 microtubule doublets surrounds a central pair of microtubules, this arrangment found in nearly all eukaryotic flagella and cilia is called

stroma

a thick fluid inside the space enclosed by the inner membrane

plasmodesmata

channels between adjacent plant cells form a circulatory and communication system connecting the cells in plant tissues the cells of a plant tissue share water, nourishment, and chemical messages

gap junctions

channels similar in function to the plasmodesmata of plants, allowing small molecules to flow between neighboring cells

nuclear pores

covers the nuclear envelope (tiny, protein-lined holes) (RNA and other materials can enter and leave the nucleus through these)

chromosome

each cromatin fiber DNA is in the form of chromosomes when chromatin coils up during cell division dense and coiled up fibers(when DNA is dividing, mitosis)

proteins

embedded in the cell membrane some of these help transfer things into and out of the cell others lie on one side of the membrane.

endomembrane system

eukaryotic organelles are formed of interrelated membranes we collectively call the...

thylakoid

hollow membranous disks

centrioles

identical to basal bodies