Chapter 6. Tour of the Cell

Question 1

How do we study Cells?

Answer 1

Microscopy

Question 2

Light Microscope

Answer 2

Visible light translated through specimen and then through glass lenses.

Question 3

Electron Microscopy

Answer 3

Focuses a beam of electrons through specimen onto the surface.

Question 4

Transmission Electron Microscope

Answer 4

Used to study internal structure cells.

Question 5

Cell Fractionzation

Answer 5

1. Homogenization= Break cells apart.

2. Differential centrifugation= sorts by size.

Question 6

Prokaryotic Cell

Answer 6

No nucleus
DNA in cytoplasm
DNA->RNA->Protein can take simultaneously.
Cell process diffusion is dependent.

Question 7

Fimbriae

Answer 7

Attachment of things. Found on the outside on a prokaryotic cell. (Little hair)

Question 8

Nucleotide

Answer 8

The smallest unit of a nucleic acid,contains 5 carbon sugars and nitrogen is the base. Has one or more phosphate groups. Found in the DNA.

Question 9

Ribosomes

Answer 9

Where protein synthesis takes place. Used by both mRNA and DNA. Found in both prokaryotic cells and eukaryotic cells. Located in cytoplasm.

Question 10

Plasma membrane (Prokaryote)

Answer 10

Phospholipid bilayer has proteins that control energy exchange for prokaryotic cells. They don’t have mitochondria so they need a different energy source.

Question 11

Flagella

Answer 11

Controls movement

Question 12

Cell wall

Answer 12

Protects the cell from environment. Associated w/ plant cells. Prokaryotes, fungi, and some protists also have a cell wall. Cell wall is thicker than the plasma membrane. Has three walls (Primary cell wall, middle lamella, and secondary cell wall)

Question 13

Capsule

Answer 13

Carbohydrates. Rich outer coating of prokaryotes.

Question 14

Cell theory

Answer 14

All organisms are composed of cells because of the surface volume ratio. necessary because many molecules of diffusion restrict cell size in order to maintain appropriate surface to volume ratio.

Question 15

Eukaryotic Cell

Answer 15

Processes nucleus where DNA resides. Extensive membrane system.

Question 16

Microvilli

Answer 16

Projection that increases the cells surface area.

Question 17

Peroxisome

Answer 17

Organelle with various specialized metabolic functions. Produces hydrogen peroxide as by product then coverts to water. A single membrane bound vesicle. Found in the Eukaryotic cell.

Question 18

Mitochondrion

Answer 18

Two membrane, outer membrane is smooth and the inner is in folds (cristae) Matrix= cytoplasm of mitchondria (enclosed by inner membrane) matrix contains DNA and ribosomes.
Where cellular respiration is occurred and most ATP is generated.

Question 19

Lysome

Answer 19

Membrane bound vesicles.
Digestive organelle where macromolecules are hydrolyzed.
Fuse with vesicles containing invaginated cell membrane.
Low pH activates enzymes, contents are digested.

Question 20

Golgi Apparatus

Answer 20

After leaving the ER transport, vesicles are sent here.
Organelle active in the synthesis, modification, sorting, and secretion of cell products.
cis face = receiving side of Golgi apparatus
trans face = shipping side.

Question 21

Ribosome

Answer 21

Complexes that make proteins free in the cytosol or other organelles

Question 22

Flagellum

Answer 22

Motility structure present in some animal cells, composed of a cluster of microtubules w/n an extension of plasma membrane.

Question 23

Centrosome

Answer 23

Found in both plant and animals cells near nucleus
Region where microtubules are initiated; contains a pair of centrioles.
organizes mitotic and meiotic spindles.
mitotic/meiotic spindles separate the daughter chromosomes.

Question 24

Cytoskeleton

Answer 24

Reinforces cells shape, functions, in cell movement, components are made up of protein. Includes (microfilaments, intermediate filaments, and microtubules.)

Question 25

Nuclear envelope

Answer 25

Double membrane enclosing the nucleus , perforated by pores; continuous with ER. Lined with nuclear lamina

Question 26

Nucleus

Answer 26

Largest organelle, double membrane, nuclear pores penetrate both membranes (nuclear lamania) non membranous structure involved in production of ribosomes has one or more nucleoli

Question 27

Chromatin

Answer 27

Material consisting DNA and proteins, visible in a dividing cell as individual condensed chromosomes

Question 28

Plasma membrane (Eukaryote)

Answer 28

Enclosing the cell

Question 29

Endoplasmic Reticulum

Answer 29

Network of membranous sacs and tubes. active in membrane synthesis and other synthetic and metabolic processes has rough ER ribosomes-studded and smooth region that lacks ribosomes.

Question 30

Difference between fimbriae, flagella, and cilia?

Answer 30

Fimbriae- attachment of things. Only Prokaryotic Flagella- controls movement. Eukaryotic/prokaryotic Cilia- sense motion and helps w/ movement. Only in Eukaryotic.

Question 31

Phagocytosis

Answer 31

amoebas and other protists eat by engulfing smaller organisms of food particles. captures external particles lysosome adds enzymes particles degraded.

Question 32

Autography

Answer 32

Defective organelle into vesicle lysosomes fuses digestion occurs. eats itself

Question 33

What kind of macromolecules do lysosomes enzymes digest?

Answer 33

Proteins, Nucleic acids, carbohydrates, and lipids.

Question 34

Centriols

Answer 34

Found only in animal cell centrosomes. Bundles of microtubules triplets. oriented at right angles to each other. basal bodies associated w/ flagellae.

Question 35

Flagella and Cilia

Answer 35

``` Same internal organization (9+2) pattern. 9 peripheral pairs microtubules. 2 central microtubules Flagella- move cells through liquid cilia- can move through the liquid. ```

Question 36

Flagellum

Answer 36

basal body (9+0) pattern just inside the plasma membrane. surrounded by extended membrane. microtubule pairs connected by motor proteins called dyneins aka radial spokes. when dyneins move, MT must bend b/c of spokes.

Question 37

Microtubules

Answer 37

``` Hollow tubes 25nm 15 nm 1D Tublin heterodimers Alpha tublin Beta tublin function: cell shape maintenance, cell motility (flagella or cilia), chromosome movements, organelle movements. ```

Question 38

Microfilaments

Answer 38

2 intertwined strands actin 7nm actin (energy) function: cell shape maintenance, cell shape changes, muscle contraction, cytoplasmic streaming, cell movement (amoeboid), cell division (cytokinesis)

Question 39

Intermediate filaments

Answer 39

Coiled fibrous proteins 8-12 nm various, including keratin function: cell shape maintenance, organelle anchorage (nucleus), nuclear lamina

Question 40

Muscle sacomers

Answer 40

Contractile unit | myosin moters in the muscle cell contraction.

Question 41

cortex

Answer 41

outer cytoplasm | gel w/ actin network

Question 42

Inner cytoplasm

Answer 42

sol / actin subunits

Question 43

Vacuole

Answer 43

non moving cortical cytoplasm (gel) chloroplast cell wall parallel actin filaments streaming cytoplasm (sol) Contractile vacuoles pump excess water out of fresh water protests. Central vacuoles are found in mature plant cell cells and are surrounded by the vacuolar membrane and enclosing the cell sap.

Question 44

cell-cell connections

Answer 44

plants move water from roots to leave via hollow tubes formed by plant cells that die leaving the cell walls behind.

Question 45

phloem

Answer 45

plants move solutes from leaves to roots or roots to leaves in living cell vessels.

Question 46

How are downward movements possible in plant cells?

Answer 46

Cytoplasmic connections between living plant cells make downward movements possible.

Question 47

Plasmaodesmata

Answer 47

membrane lined channels filled w/ cytoplasm

Question 48

What makes several kinds of cell-cell contacts?

Answer 48

Epithelial cells

Question 49

What do tight junctions do?

Answer 49

Hold cells together to create barriers

Question 50

Desnosome

Answer 50

Reinforced cell connection

Question 51

Gap junction

Answer 51

cytoplasm & cytoplasm connection (animal analog of plasmodesmata)