Chapter 6

Question 1

Microscopy

Answer 1

A technical field that uses microscopes to view objects and areas of objects that cannot be seen with the naked eye

Question 2

Light (visible)

Answer 2

Visible light is passed through the specimen & then through glass lenses. Refracts light in a way, becomes bigger
380 - 700 nm.

Question 3

Magnification

Answer 3

Ratio of an objects (visual) size to real size

Question 4

Resolution

Answer 4

A measure of clarity of image; it is the minimum distance between 2 points that can be separated and still be distinguished as separate points. Inversely related to wavelength. As resolution increases, wavelength decreases.

Question 5

Wavelength

Answer 5

The distance over which a wave’s shape repeats. Inversely related to resolution. As wavelength increases, resolution decreases.

Question 6

Contrast

Answer 6

Difference in brightness between light & dark areas

Question 7

Stain

Answer 7

A discoloration that can be clearly distinguished from the surface, material, or medium it is found upon

Question 8

Condenser

Answer 8

Device used to condense a substance from its gaseous to its liquid state

Question 9

Robert Hooke

Answer 9

Cells. 1665. Dead bark.

Question 10

Light Microscope (LM)

Answer 10

visible light is passed through the specimen and then through glass lenses. The lenses refract (bend) the light in such a way that the image of the specimen is magnified as it is projected into the eye or into a camera.

Question 11

Electron microscope (EM)

Answer 11

Focuses a beam of electrons through the specimen or onto its surface. Electron beams have much shorter wavelengths than visible light.

Question 12

SEM-Scanning EM

Answer 12

Scans surface, usually coated w/ a thin film of gold. Beam excites electrons on surface, secondary electrons are detected by device that translates pattern of e- into an electronic signal sent to a vid screen. 3D.

Question 13

TEM- Transmission EM

Answer 13

Internal part of cell. The TEM aims an electron beam through a very thin section of the specimen. For the TEM, the specimen has been stained with atoms of heavy metals, which attach to certain cellular structures, thus enhancing the electron density of some parts of the cell more than others. The electrons passing through the specimen are scattered more in the denser regions, so fewer are transmitted.

Question 14

Centrifuge(use)

Answer 14

Useful in cell fractionation, takes cell apart. Spins test tubes holding mixtures of disrupted cells at different speeds->results: subset of cell component comes to rest on bottom

Question 15

Cell Fractionation

Answer 15

Takes cell apart & separates major organelles & other subcellular structure from one another.

Question 16

Prokaryota

Answer 16

Domain Bacteria/Archaea. Avg. bacteria: 1-5 micrometers. DNA is concentrated in a region that is not membrane-enclosed, called the nucleoid

Question 17

Eukaryota

Answer 17

Domain Eukarya. Avg. Eukarya cell: 10-100 micrometers. DNA in an organelle called nucleus. Bound by a double membrane

Question 18

Cytoplasm

Answer 18

Semifluid substance of a cell that’s external to the nuclear membrane, internal to the cellular membrane. Region between nucleus & plasma membrane.

Question 19

Surface vs Volume of Cell

Answer 19

Smaller cell = greater ratio of surface area to volume. Plasma membrane to use.

Question 20

Diffusion

Answer 20

The net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration.

Question 21

Membrane Structure

Answer 21

Phospholipid bilayer + glycoproteins. ECM and microfilaments. Figure 6.6

Question 22

Animal v Plant cells

Answer 22

Figure 6.8

Question 23

Nucleus

Answer 23

Contains most of the genes in the eukaryotic cells.

Question 24

Nuclear Envelope

Answer 24

Encloses Nucleus, separating its contents from the cytoplasm. A double membrane.

Question 25

Nuclear Pores

Answer 25

Protein-lined channel in the nuclear envelope that regulates the entry and exit of proteins and RNAs, as well as large complexes of macromolecules

Question 26

Nuclear matrix

Answer 26

a framework of protein fibers extending throughout the nuclear interior. Functions include gene expression, RNA splicing, and nuclear protein import/ export.

Question 27

Chromatin

Answer 27

A complex of DNA and proteins called histones that packages the DNA double helix into a compact form that can fit in the cell nucleus.

Question 28

Chromosomes

Answer 28

Structure that carry the genetic information. Each chromosome contains one long DNA molecule associated with many proteins.

Question 29

Nucleolus

Answer 29

A mass of densely stained granules and fibers adjoining part of the chromatin. Where a type of RNA called ribosomal RNA (rRNA) is synthesized from genes in the DNA. Ribosomal proteins are also stored here.

Question 30

Ribosomes

Answer 30

Complexes made of ribosomal RNAs and proteins. Site of protein synthesis.

Question 31

Ribosome Function

Answer 31

Cellular components that carry out protein synthesis

Question 32

Free vs. Bound Ribosomes

Answer 32

Free ribosomes are suspended in the cytosol, while bound ribosomes are attached to the outside of the endoplasmic reticulum or the nuclear envelope.

Question 33

Endomembrane System

Answer 33

The different membrane-bounded organelles of the eukaryotic cell. Include nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, various vesicles and vacuoles, and the plasma membrane.

Question 34

Endoplasmic Reticulum(ER)

Answer 34

An extensive network of membrane that accounts for more than 1/2 of the total membrane in many eukaryotic cells. Endoplasmic: Within the cytoplasm. Reticulum: Latin for little net. The ER consists of a network of membranous tubules and sacs called cisternae.

Question 35

# What is Cytosol

Answer 35

Cytosol is the fluid part of cytoplasm. Similar to cytoplasm.

Question 36

Cisternal Space

Answer 36

ER lumen (cavity). The ER membrane separates the internal compartment of the ER, called the CISTERNAL SPACE, from the cytosol.

Question 37

Rough ER

Answer 37

Studded with ribosomes on the outer surface of the membrane and thus appears rough through the electron microscope. Connected to the smooth ER.

Question 38

Functions of rough ER

Answer 38

Many cells secrete proteins that're produced by ribosomes attached to rough ER. Secretory proteins. Mostly glycoproteins, proteins with carbohydrates covalently bonded to them.

Question 39

Smooth ER

Answer 39

Outer surface lacks ribosomes. Connected to the rough ER.

Question 40

Functions of Smooth ER

Answer 40

Diverse metabolic processes, vary with cell type. Including: Synthesis of lipids (sex hormones of vertebrates), metabolism of carbohydrates, detoxification of drugs and poisons, and storage of calcium ions. It's also a membrane factory for the cell; it grows by adding membrane proteins and phospholipids to its own membrane.

Question 41

Golgi Apparatus

Answer 41

A warehouse for receiving, sorting, shipping, and even some manufacturing. Products of the ER, such as proteins, are modified and stored and then sent to other destinations. Modifies some molecules that it's transporting. Also manufactures some macromolecules.

Question 42

Golgi Apparatus "Faces"

Answer 42

A Golgi stack has a distinct structural directionality, with the membranes of cisternae on opposite sides of the stack differing in thickness and molecular composition. The two sides of a Golgi stack are referred to as the cis face and the trans face; these act, respectively, as the receiving and shipping departments of the Golgi apparatus. Cis face: close to ER.

Question 43

Lysosomes

Answer 43

A membrane sac of hydrolytic enzymes that many eukaryotic cells use to digest (hydrolyze) macromolecules. Inside = acidic. pH of 4-4.5ish

Question 44

Vacuoles

Answer 44

Large vesicles derived from the ER and Golgi apparatus. Thus, vacuoles are an integral part of a cell's endomembrane system. Vacuolar membrane is selective in transporting solutes; as a result, the solution inside a vacuole differs in composition from the cytosol. Mature plants contain a large central vacuole. Contractile vacuoles: pump excess water out of the cell.

Question 45

"Non-system" membrane Organelles

Question 46

Endosymbiont theory

Answer 46

This theory states that an early ancestor of eukaryotic cells engulfed an oxygen using non-photosynthetic prokaryotic cell. It becomes endosymbiont (cell living within another cell). Evolution-becomes a singular organism, a eukaryotic cell, endosymbiont became the mitochondrion.

Question 47

Mitochondrion

Answer 47

Plural: Mitochondria. Sites of cellular respiration.

Question 48

Cellular respiration

Answer 48

The metabolic process that uses oxygen to drive the generation of ATP by extracting energy from sugars, fats, and other fuels.

Question 49

Intermembrane space

Answer 49

The inner membrane enclosing the mitochondrion divides it into two internal compartments. The first is intermembrane space, the narrow region between the inner and outer membranes.

Question 50

Mitochondrial matrix

Answer 50

The inner membrane enclosing the mitochondrion divides it into two internal compartments. The second compartment, the mitochondrial matrix, is enclosed by the inner membrane. Contains many different enzymes as well as the mitochondrial DNA and ribosomes.

Question 51

Cristae

Answer 51

Of the two membranes enclosing the mitochondria, the inner membrane is convoluted, with infoldings called CRISTAE.

Question 52

Chloroplasts

Answer 52

Found in plants and algae, are the sites of photosynthesis.

Question 53

Stroma

Answer 53

The fluid inside the chloroplast, outside the thylakoids, which contains the chloroplast DNA and ribosomes as well as many enzymes.

Question 54

Thylakoids

Answer 54

Inside the chloroplast, another membranous system in the form of flattened interconnected sacs.

Question 55

Thylakoid space

Answer 55

A continuous exoplasmic cellular space that is poorly characterized compared to the other chloroplast compartments

Question 56

Thylakoid membranes

Answer 56

A membrane-bound compartment inside chloroplasts and cyanobacteria that is the site of photochemical and electron transport reactions of oxygenic photosynthesis

Question 57

Granum (grana)

Answer 57

A stack of thylakoids.

Question 58

(Amyloplasts)

Answer 58

Colorless, non-pigment-containing organelles found in plant cells. Stores starch (amylose), particularly in roots and tubers.

Question 59

(Chromoplasts)

Answer 59

Heterogeneous organelles responsible for pigment synthesis and storage in specific photosynthetic eukaryotes. Has pigments that give fruits and flowers their orange and yellow hues.

Question 60

Peroxisomes

Answer 60

Specialized metabolic compartment bounded by a single membrane. Contain enzymes that remove hydrogen atoms from various substrates and transfer them to oxygen, producing hydrogen peroxide as a by-product. Immediately breakdown peroxisome afterwards.

Question 61

Cytoskeleton

Answer 61

A network of fibers extending throughout the cytoplasm.

Question 62

Motor Proteins

Answer 62

Cell motility generally requires interaction of the cytoskeleton and MOTOR PROTEINS. ATP powers motor protein to use the microtubule as a road to transport vesicles

Question 63

Microtubules

Answer 63

Biggest cytoskeleton part. Hollow rods constructed from globular proteins called tubulins. Flagella and Cilia. Both arranged with 9 around and 2 in the middle (9+2), doublets of microtubules. Bases of flagella and cilia are different, arranged with 9 around and 0 in the middle (9+0(basal body)), triplets of microtubules. Consistent

Question 64

Centrosome

Answer 64

In ANIMAL cells, microtubules grow out from a centrosome, a region that is often located near the nucleus. Within the centrosome is a pair of centrioles (made of microtubules).

Question 65

Microfilaments

Answer 65

Smallest cytoskeleton part. Thin solid rods. Also called actin filaments because they're build from molecules of actin, a globular protein. A microfilament is a twisted double chain of actin subunits. 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. Present in all eukaryotic cells. Consistent.

Question 66

Intermediate Filaments

Answer 66

Named after their diameter, larger than microfilaments but smaller than microtubules. Only found in the cells of some animals, including vertebrates. Specialized for bearing tension. Diverse class of cytoskeletal element. Each type is constructed from a particular molecular subunit belonging to a family of proteins. Vary.

Question 67

Amphipathic

Answer 67

Containing both hydrophilic and hydrophobic parts.

Question 68

Dynein

Answer 68

Large motor protein. Attached along each outer microtubule doublet. Has two "feet" that "walk" along the microtubule of the adjacent doublet, using ATP for energy.

Question 69

Myosin motor activity

Answer 69

Thousands of actin filaments and thicker filaments made of a protein called myosin interact to cause contraction of muscle cells.

Question 70

Pseudopodia

Answer 70

A cell crawls a long a surface by extending cellular extensions called pseudopodia. pseudes-false and pod-foot.

Question 71

Cytoplasmic streaming

Answer 71

In plant cells, actin-protein interactions contribute to CYTOPLASMIC STREAMING, a circular flow of cytoplasm within cells. This movement is especially common in large plant cells, speeds the movement of organelles and the distribution of materials within the cell.

Question 72

Microvilli

Answer 72

Singular: microvillus. Delicate projections that increase the cell's surface area. The core is made up of bundles of microfilaments.

Question 73

Plant Cell Walls

Answer 73

Extracellular structure of plant cells. Protects the plant cell, maintains its shape, and prevents excessive uptake of water. At the level of the whole plant, upholds it against gravity. Some prokaryotes, protists and fungi also have cell walls. Primary cell wall, middle lamella, and a secondary cell wall.

Question 74

Primary cell wall

Answer 74

Relatively thin and flexible wall. First one secreted.

Question 75

Middle Lamella

Answer 75

Between primary walls of adjacent (plant)cells. Thin layer rich in sticky polysaccharides called Pectins.

Question 76

Secondary cell wall

Answer 76

Between the plasma membrane and the primary wall. Often deposited in several laminated layers, strong and durable matrix that affords cell protection and support. i.e. wood is mostly secondary wall.

Question 77

Extracellular Matrix (ECM)

Answer 77

Animal version of cell wall. Mainly glycoproteins and other carbohydrate-containing molecules secreted by the cells. Most abundant glycoprotein is collagen.

Question 78

Collagen

Answer 78

Forms strong fibers outside the cells. ECM. Accounts for about 40% of the total protein in the human body.

Question 79

Intracellular Junctions

Answer 79

Plant cells connected via plasmodesmata channels. The plasma membrane of adjacent cells line the channel of each plasmodesma and thus are continuous.

Question 80

Cell Junctions in Animal Cells

Answer 80

Tight Junctions, Desmosomes, and gap junctions. (Gap junctions are most like the plasmodesmata of plants, although gap junction pores are not lined with membrane-rather, they consist of proteins extending from each cell's membrane that form a connecting pore.)