Chapter 4 & 5

Question 1

Prokaryotic cells consist of?

Answer 1

Bacteria and archaea

Question 2

What is a major difference between prokaryotic and eukaryotic cell?

Answer 2

Where each holds their DNA. In a eukaryotic cell, most of the DNA is stored in the nucleus which is an organelle bounded by a double membrane. In prokaryotic cells, the DNA is concentrated in the nucleoid, a region that is not bounded by a membrane.

Question 3

Eukaryotic cell is what? Define it

Answer 3

A type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles. Organisms with eukaryotic cells (protists, plants, fungi, and animals) are called eukaryotes.

Question 4

Define prokaryotic cell

Answer 4

A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles. Organisms with prokaryotic cells (bacteria and archaea) are called prokaryotes.

Question 5

Which cells are generally larger, prokaryotic or eukaryotic?

Answer 5

Eukaryotic

Question 6

What is an endomembrane?

Answer 6

The collection of membranes inside and surrounding a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles; includes the plasma membrane, the nuclear envelope, the smooth and rough endoplasmic reticulum, the Golgi apparatus, lysosomes, vesicles, and vacuoles.

Question 7

Chloroplast

Answer 7

organelle found in plants and photosynthetic protists that absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water.

Question 8

Dyneins

Answer 8

Motor proteins. cilia and flagella, a large motor protein extending from one microtubule doublet to the adjacent doublet. ATP hydrolysis drives changes in dynein shape that lead to bending of cilia and flagella.

Question 9

Intercellular junctions?

Answer 9

Intercellular junctions provide plant and animal cells with the ability to communicate through direct contact.

Question 10

What are the three main types of intercellular links?

Answer 10

Cells adhere, interact, and communicate. Note these are only in animal cells.

Question 11

Example of cells adhere?

Answer 11

• Tight junctions (fused, forming continuous belts around cells. Prevents leakage of extra cellular fluid. Example: intestinal epithelium

Question 12

Example of interact?

Answer 12

epithelium

- Desmesomes: anchoring junctions (fasten cells together into strong sheets, like brads in a binder)

Question 13

Example of communicate?

Answer 13

gap junctions: communicating junctions that provide cytoplasmic channels between adjacent cells. Special membrane proteins. Used in interaction between heart cells, because they all must contract at the same time. So signal is sent through this by gap junctions. Another example is embryological development.

Question 14

Eukaryotic cells consist of?

Answer 14

Protists, animal, fungi, and plants

Question 15

Who do prokaryotic cells lack?

Answer 15

Nucleus and membrane bound organelles

Question 16

What is compartmentalization?

Answer 16

Compartmentalization allows eukaryotic cells to perform otherwise incompatible chemical reactions simultaneously. It also increases the surface area of the cell membranes, which are necessary for obtaining nutrients and excreting waste. Thus, compartmentalization is a means of increasing membrane area without increasing the size of the cell.

Question 17

Er?

Answer 17

An extensive membranous network in eukaryotic cells, continuous with the outer nuclear membrane and composed of ribosome-studded (rough) and ribosome-free (smooth) regions. Accounts for more than half of the total membrane in eukaryotes. It separates the internal compartment of the er from the cytosol.

Question 18

Smooth er?

Answer 18

That portion of the endoplasmic reticulum that is free of ribosomes. Functions: synthesis of lipids, metabolism of carbohydrates, detoxifications of drugs and poison, and storage of calcium ions.

Question 19

Rough er?

Answer 19

That portion of the endoplasmic reticulum with ribosomes attached. Functions: making secretory proteins, it’s a membrane factory for the cell.

Question 20

Central vacuole?

Answer 20

In a mature plant cell, a large membranous sac with diverse roles in growth, storage, and sequestration of toxic substances. Plays role in the growth of plant cells.

Question 21

Cytoskeleton?

Answer 21

It’s a network and is involved in many forms of support and cell movement. Made of up three types of fibers called Microtubules, micro filaments, and intermediate filaments. Plays huge role in muscle cell and neuron cell, and paramecium (single celled organism).

Question 22

Micro tubules

Answer 22

Thicket, used as “tracks” if something has a motor protein. Also separate chromosomes during mitosis, and are the main part of chili and flagella.

Question 23

Micro filaments

Answer 23

“Action filaments”, tension bearing. Can form structural networks when certain proteins bind along the side of such a filament and allow a new filament to extend as a branch.

Question 24

Intermediate filaments

Answer 24

Framework for the entire cytoskeleton, ie axons if nerve cells.

Question 25

Cilia and flagella

Answer 25

Cilia and flagella are cellular appendages that are capable of specific types of movement. The movement of these appendages allows the cell to move or to fulfill specific tasks. Flagella are relatively long tail-like structures that are capable of either undulating or rotational movement. Cilia are numerous shorter projections located around the outside of a cell. By beating in near-unison with a whip-like motion, cilia can move cells from one place to another or assist in transporting external substances.

Question 26

Nucleus

Answer 26

Consist of nucleolus, nuclear envelope, and chromatin. Found in eukaryotes. Contains DNA with a varied of proteins to form chromosomes

Question 27

Who came first, prokaryotic or eukaryotic cells?

Answer 27

Prokaryotic cells

Question 28

Golgi (vesicles)

Answer 28

Golgi apparatus is An organelle in eukaryotic cells consisting of stacks of flat membranous sacs that modify, store, and route products of the endoplasmic reticulum and synthesize some products, notably noncellulose carbohydrates. Vesicles contracted in the vicinity of the Golgi apparatus are engaged in the transfer of material between parts of the Golgi and other structures.

Question 29

Golgi apparatus and vesicles

Answer 29

The Golgi apparatus packages proteins into membrane-bound vesicles inside the cell before the vesicles or sent to their destination

Question 30

Centrosome

Answer 30

Is on organelle that serves as the main microtubule organizing center of the animal cell as well as a regulator of cell cycle progression. Function: production of micro tubules, help regulate mitosis.

Question 31

Plant cell walls

Answer 31

Found only in plants. The function of the cell wall is to provide support and production for the cell. primary secreted first

Question 32

Ribosomes

Answer 32

A complex of rRNA and protein molecules that functions as a site of protein synthesis in the cytoplasm; consists of a large subunit and a small subunit. In eukaryotic cells, each subunit is assembled in the nucleolus. See also nucleolus. Two types: bound (attached to outside of er or nuclear envelope) and free (in the cytosol)

Question 33

Centrosome

Answer 33

A structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center and is important during cell division. A centrosome has two centrioles.

Question 34

Motor protein

Answer 34

A protein that interacts with cytoskeletal elements and other cell components, producing movement of the whole cell or parts of the cell.

Question 35

Lysosome

Answer 35

A membrane-enclosed sac of hydrolytic enzymes found in the cytoplasm of animal cells and some protists. Work best in acidic environment. Animal cell uses them to digest (hydrolyz) macromolecules.

Question 36

Mitochondrion

Answer 36

An organelle in eukaryotic cells that serves as the site of cellular respiration; uses oxygen to break down organic molecules and synthesize ATP.

Question 37

Peroxisomes

Answer 37

An organelle containing enzymes that transfer hydrogen atoms from various substrates to oxygen (O2), producing and then degrading hydrogen peroxide (H2O2).

Question 38

Fluid mosaic model

Answer 38

The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of protein molecules drifting laterally in a fluid bilayer of phospholipids.

Question 39

Role of cholesterol/temperature

Answer 39

Acts as a temperature buffer (buffer is something that works against extremes, in chemical stuff it is something that works against something such as acidity). A buffer keeps a balance.

• in warmer temperatures, it makes membrane less fluid (saturated)
• in cool temperatures, it prevents membrane from solidifying (unsaturated)

Question 40

Factors that affect fluidity

Answer 40

Unsaturated hydrocarbons: remain fluid at lower temperatures

Example for animal: polar bear

Question 41

Factors that affect fluidity part 2

Answer 41

Saturated hydrocarbons: solidify at higher temperatures

Example for animal: camel

Question 42

Facilitated diffusion. Types?

Answer 42

Process by which ions and hydrophilic substances diffuse across the membrane. Two major groups of integral membrane proteins are involved in facilitated diffusion: carrier proteins (glucose carrier protein) and ion channels (sodium ion channels and post assist ion channels and one other type that only lets one substance through). Type of passive transport

Question 43

Integral proteins

Answer 43

A transmembrane protein with hydrophobic regions that extend into and often completely span the hydrophobic interior of the membrane and with hydrophilic regions in contact with the aqueous solution on one or both sides of the membrane (or lining the channel in the case of a channel proteins. RUNS THROUGH WHOLE MEMBRANE OR IS EMBEDDED ON THE INSIDE OF IT

Question 44

Peripheral proteins

Answer 44

A protein loosely bound to the surface of a membrane or to part of an integral protein and not embedded in the lipid bilayer. FOUND ON THE OUTSIDE OF MEMBRANE, this protein can be hydrophilic

Question 45

Electrochemical gradient

Answer 45

The diffusion gradient of an ion, which is affected by both the concentration difference of an ion across a membrane (a chemical force) and the ion’s tendency to move relative to the membrane potential (an electrical force).

Question 46

Diffusion

Answer 46

Potential energy gradient, molecules move down their concentration gradient, does not require the cell to use energy, causes many substances to move across a cell membrane, it’s a type of passive transport.

Question 47

Carrier proteins

Answer 47

Involved in facilitated diffusion and active transport of substances into or out of the cell

Question 48

Active transport

Answer 48

Moving substances against their concentration gradient, energy needed in the form of ATP to do this.

Question 49

Active transport sodium potassium pump

Answer 49

3 sodium moved out of protein and 2 post assign moved in. (More positive charge on outside and less negative charge on inside) . Phosphate comes of ATP and attaches to a protein channel to change its shape for either sodium or postassium. This creates a membrane potential because the inside of the cell is more negative and positive ions on the outside are attracted to it… Needs an electrochemical gradient.

Question 50

Endocytosis

Answer 50

(en′-dō-sī-tō′-sis) Cellular uptake of biological molecules and particulate matter via formation of vesicles from the plasma membrane.

Question 51

Exocytosis

Answer 51

(ek’-sō-sī-tō′-sis) The cellular secretion of biological molecules by the fusion of vesicles containing them with the plasma membrane.

Question 52

Osmosis

Answer 52

(oz-mō′-sis) The diffusion of free water molecules across a selectively permeable membrane.

Question 53

Aquaporin

Answer 53

A channel protein in the plasma membrane of a plant, animal, or microorganism cell that specifically facilitates osmosis, the diffusion of free water across the membrane.

Question 54

Amphipathic

Answer 54

(am’-fē-path′-ik) Having both a hydrophilic region and a hydrophobic region.

Question 55

Ion channel

Answer 55

Part of facilitated diffusion. Type of channel that only lets one substance go through.

Question 56

Cellular membrane structure/parts

Answer 56

Cell membrane is a phospholipid bilayer. It is impermeable cause it lets some things in while keeping others out. Has two types of membrane proteins: proriferal and integral. As long as the cell membrane is moving, stuff can move inside and outside of the cell. Once it stops moving the cell will die. It provides support and protection. They must be fluid to work properly.

Question 57

Turgor pressure

Answer 57

Turgurnpressure pushes the plasma membrane against the cell wall of plant, fungi, and bacteria cells as well as those protist cell which have cell walls.

Question 58

Nuclear envelope

Answer 58

In a eukaryotic cell, the double membrane that surrounds the nucleus, perforated with pores that regulate traffic with the cytoplasm. The outer membrane is continuous with the endoplasmic reticulum.

Question 59

Nucleolus

Answer 59

plural, nucleoli) A specialized structure in the nucleus consisting of chromosomal regions containing ribosomal RNA (rRNA) genes along with ribosomal proteins imported from the cytoplasm; site of rRNA synthesis and ribosomal subunit assembly. See also ribosome.

Question 60

Chromatin

Answer 60

(krō′-muh-tin) The complex of DNA and proteins that makes up eukaryotic chromosomes. When the cell is not dividing, chromatin exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope.

Question 61

Glycoproteins

Answer 61

A protein with one or more covalently attached carbohydrates.

Question 62

Cytoskeleton functions?

Answer 62

Support and mobility and ,armor role in organizing the structures and activities of the cell.