Chapter 6: A Tour of the Cell Flashcards

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1
Q

Cell

A

Simplest collection of matter considered to be living

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2
Q

Light Microscope

A

Visible light passes through the specimen, then through the glass lenses, bending (refracting) the light to magnify the image

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3
Q

Magnification

A

The ratio of an objects image size to its real size

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4
Q

Resolution

A

Measure of the clarity of the image. The minimum distance that 2 points can be separated and still be distinguished as separate points

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5
Q

Contrast

A

The difference in brightness between the light and dark areas of an image

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6
Q

Organelles

A

The membrane-enclosed structures within eukaryotic cells

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7
Q

Prokaryotic cell

A

Organisms of the domains bacteria and Archaea have prokaryotic celss

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8
Q

Eukaryotic

A

Cells in protists, fungi, animals, and plants

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9
Q

Cytosol

A

Jelly-like substance that subcellular components are suspended in

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10
Q

nucleoid

A

non-membrane enclosed structure in a prokaryotic cell that is concentrated with DNA

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11
Q

cytoplasm

A

inside a cell; the region between the nucleus and the plasma membrane

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12
Q

plasma membrane (cell membrane)

A

the boundary of every cell, serves as a barrier that allows passage in/out of the cell (oxygen, nutrients, waste)

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13
Q

Nucleus

A

in a eukaryotic cell, organelle enclosed by a membrane that contains DNA (genes)
Consists of Nuclear Envelope, Nucleolus, and Chromatin

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14
Q

Nucleolus

A

nonmembranous structure involved in production of ribosomes; contained in the nucleus

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15
Q

chromosomes

A

structure that carries genetic information

contains: 1 dna molecule and many proteins

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16
Q

ribosome

A

complexes made of rRNA and proteins

-cellular components that perform protein synthesis

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17
Q

free ribosomes

A

ribosomes that are suspended in the cytosol

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18
Q

bound ribosomes

A

attached to the endoplasmic reticulum or nuclear envelope

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19
Q

rRNA

A

(ribosomal RNA) RNA molecules that together with protein make up ribosomes

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20
Q

mRNA

A

Messenger RNA, Rattaches to ribosomes in the cytoplasm to specify the primary structure of the protein

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21
Q

endomembrane system

A

collection of membranes inside and surrounding a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles

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22
Q

Vesicles

A

sacs made of membrane

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23
Q

endoplasmic reticulum

A

extensive membranous network in a eukaryotic cell;continuous with the outer nuclear membrane and composed of ribosome studded (rough) and ribosome free (smooth) regions

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24
Q

Smooth ER

A

Outer surface of a portion of the endoplasmic reticulum that lacks ribosomes; functions in diverse metabolic processes (lipid synthesis, carb metabolism, detox, storing calcium)

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25
Q

Rough ER

A

Studded with ribosomes, makes secretory proteins and makes membranes

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26
Q

Golgi Apparatus

A

Organelle active in synthesis, modification, sorting, and secretion of cell products

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27
Q

Vacuoles

A
Large vesicles (membranous sacs) derived from ER and golgi apparatus
Broken down into 3 categories:
Food, contractile, central
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28
Q

Food vacuoles

A

A membranous sac created when a eukaryotic cell “eats” a smaller particle or microorganism by phagocytosis

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29
Q

Contractile Vacuole

A

Helps move excess water out of fresh water protists

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30
Q

Central vacuoles

A

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

31
Q

Mitochondria

A

Convert energy for cellular work.

-cell respiration (uses oxygen to drive generation of ATP by extracting energy from sugars fats and fuels)

32
Q

Chloroplasts

A

Sites of photosynthesis

-uses light to drive synthesis of organic compounds (like sugars) from C02 and water

33
Q

Endosymbiont Theory

A

An early ancestor eukaryotic cells engulfed an oxygen-using non-photosynthetic prokaryotic cell. eventually the engulfed cell formed a relationship with the host in which it was enclosed becoming an Endosymbiont, a cell living within another cell. Which led to the evolution of a photosynthetic prokaryote becoming the ancestor of a eukaryote w/ chloroplasts

34
Q

Cristae

A

Smooth inner membrane of a mitochondrion that splits the organelle into 2 parts: the intermembrane space and the mitochondrial matrix

35
Q

Mitochondrial Matrix:

A

The compartment of the mitochondrion enclosed by the Cristae (inner membrane), contains enzymes and DNA and ribosomes and substrates for the citric acid cycle

36
Q

Thylakoids

A

Flat vacuole in a chloroplast. Exist in interconnected stacks called grana, convert light energy to chemical energy

37
Q

Stoma

A

Microscopic pore in the epidermis of leaves, allow gas exchange

38
Q

Perioxisomes

A

Organelle containing enzymes that hydrogen atoms to substrates of O2, producing and then degrading hydrogen peroxide (h2o2)

39
Q

Cell theory

A

All organisms are made up of 1 or more cells. Cells are the basic unit of life. All cells are derived from previous cells.

40
Q

Why do we use microscopes?

A

To closely study what cannot be observed by the naked eye. They provide magnification, high res, and contrast

41
Q

3 important parameters of microscopy

A

Magnification: making the image bigger (image:real ratio)
Resolution: making the image clearer (min distance to be distinguished)
Contrast: changing the light/dark so the components stand out

42
Q

2 types of electron microscopes, describe

A

Scanning Electron Microscope:
Shows 3d surface

Transmission Electron Microscope:
Shows thin cross sections

43
Q

Basic Features of all Cells

A
  • plasma membrane (cell membrane)
  • cytosol
  • chromosomes
  • ribosomes
44
Q

Describe prokaryotic cells

A

Prokaryotes are bacteria and archaea. They are cell that like organelles. So, other than the plasma membrane, no membranes. They have a nucleoid, rather than a nucleus, and instead of organelles floating in cytosol, prokaryotes have their proteins, ribosomes, and chromosomes suspended straight in their cytoplasm

45
Q

Describe Eukaryotic cells

A

Tonsss of membranes. Nucleus, organelles. Membranes membranes membranes. Plants and animals and fungi and these little things called protists are all eukaryotes.

46
Q

Cytosol vs Cytoplasm

A

Cytosol:
The jelly-like (semifluid) part of the Cytoplasm

Cytoplasm: fluid within the plasma membrane
-but not in the nucleus of eukaryotes

47
Q

Nucleus: what is it? what does it do, what does it make?

A

Organelle in eukaryotic cells that contains DNA, it makes ribosomes and RNA, which make proteins

48
Q

What is the nucleolus? What does it produce?

A

Nonmembranous structure within the nucleus that produces ribosomes

49
Q

Compare/Contrast ribosomes

A

Ribosomes are either free or bound.
Free ribosomes float freely in the cytosol
Bound ribosomes are bound to the ER or nuclear envelope

They both build proteins, but bound ribosomes usually make proteins for secretion (like the pancreatic cells secrete digestive enzymes)

50
Q

Discuss the endomembrane system

A

It is the system of membrane bounded organelles inside of a eukaryotic cell, including the nuclear envelope the ER, the Golgi apparatus, lysosomes, and the plasma membrane. The membranes of this system have are related, but are not identical in structure or function but they help with protein synthesis, metabolism, movement of lipids, and detox. they can also be transported by vesicles or directly contact each other.

51
Q

Compare and contrast smooth and rough ER

A

Smooth has no ribosomes.
-make lipids, metabolize carbs, detox drugs, store calcium

Rough has ribosomes.

  • it makes secretory proteins like insulin and transports them out in vesicles
  • makes transport vesicles
  • makes lipids into new membranes

Both make lipids.

52
Q

discuss the cis and trans surfaces of the golgi apparatus

A

Sections of Golgi Apparatus act as a “shipping and recieving” warehouse for the cell.

Cis: “same side”

  • faces ER
  • “Receiving”, accepts vesicles from ER by merging membranes and contents

Trans: “opposite side”

  • does not face ER
  • “Shipping”, pinches off membranes around materials to send to the rest of the cell
53
Q

Discuss the structure of the mitchondria

A
  • enclosed by two membranes, made of phospholipid bilayers and some embedded proteins
  • outer membrane is smooth
  • inner membrane (called cristae) folds
  • separate the Mitochondrion into 2 parts
  • the inter-membrane space (b/w the two membranes)
  • the mitochondrial matrix (which is where all the work gets done)
  • cristae increase the surface area of the matrix, enhancing cellular respiration
  • Mitochondria change their shape to perform.
54
Q

Discuss the structure of chloroplasts

A
  • lens shaped
  • double membrane
  • intermembrane space (b/w two membranes)
  • thylakoids (flattened, connected stacks called grana)
  • Stroma considered 3rd part of chloroplast (liquid between thylakoids)
  • Stroma contains dna ribosomes and enzymes)
55
Q

Compare and Contrast Mitochondria and Chloroplasts

A

Both M and C are responsible for energy conversion inside the cell. Both are double membranous. Both inner membranes have convoluted structures to maximize the space for energy conversion. Both structures change shape, split, and merge like structures.

M uses cellular respiration to generate ATP from sugars, fats, oxygen, and other molecules.
C converts light energy to chemical energy via photosynthesis.

56
Q

Discuss the similarities and differences among organelles that have double membranes

A

Examples of double membranous structures are Mitochondria and Chloroplasts.

Similarites:

  • work is done in inner layer
  • change shape constantly
  • autonomous/grow reproduce inside cell
  • inner layers are very complicated structures
  • contain dna and ribosomes

Differences:
-inner structures wildly different in shape and function

57
Q

Granum

A

the individual stack of the thylakoid inside a chloroplast

think like poker chip stacks

58
Q

stroma

A

fluid in the inner membrane of the chloroplast

-contains ribosomes, dna, and enzymes

59
Q

cytoskeleton

A

network of microtubules, microfilaments, and intermediate filaments that extend throughout the cytoplasm and serve a variety of mech., transport, and signaling functions

60
Q

microtubules

A
  • a hollow rod composed of tubulin proteins ( i swear thats not a made up name) that make up part of the cytoskeleton
  • found in cilia and flagella
61
Q

microfilaments

A

cable composed of actin proteins in the cytoplasm of (almost all) eukaryotic cells, makes up cytoskeleton, sometimes combines with myosin to cause cell contraction
-aka actin filament

62
Q

intermediate filaments

A

component of the cytoskeleton that includes filaments intermediate b/w microtubules and microfilaments

63
Q

cytoplasmic streaming

A
  • circular flow of cytoplasm
  • interacts with myosin and actin filaments
  • speed the distribution of materials
64
Q

cell wall

A
  • protective layer external to the plasma membrane
  • (in plants, fungi, prokaryotes, and protists)
  • polysaccharides are structural components
65
Q

extracellular matrix (ECM)

A
  • meshwork surrounding animal cells
  • consists of polysaccharides secreted by the cell
  • made of weird stuff like glyco-proteins and proteoglycans if you can even remember the name of those
66
Q

cell junctions

A

sites of direct contact between cells

-communicate, interct, adhere to eachother

67
Q

plasmodesmata

A
  • perforations in plant cell walls that connect plant cells

- unifies plant into one living continuum

68
Q

describe the 3 kinds of filaments in the cytoskeleton and their differences

A

microtubules: hollow rods made of tubulin protein
- compression resistant
- guide motor organelles through cytoplasm

intermediate filaments: in between diameters of microtubules and microfilaments

  • only found in animals
  • reinforce the shape of the cell

microfilaments: solid cables made out of actin (and sometimes myosin for contractile purposes)
- bears tension for transport of vesicles
- structural network

69
Q

two motor proteins associated with cell motility?

A

dyneins walk along microtubules

myosin cause contraction of muscle cells and play a role in cytoplasm streaming

70
Q

_____ control the beating of _____ and ______.

A
  • microtuble doublets bending
  • cilia
  • flagella
71
Q

what are the 3 layers of the cell wall?

A

middle lamella-thin layer of pectins that glues adjacent cells, between primary cell walls

primary cell wall-thin flexible cell wall a young plant cell secretes, hardens on maturation

secondary cell wall- between the plasma membrane and primary wall
-strong double matrix supports plant cells (think of wood)

72
Q

ECM proteins bind to the receptor proteins in the plasma membrane called ______.

A

-integrins

73
Q

list and define the 3 types of cell junctions

A

-plasmodesmata: pathways between plant cells that allow adherence, interaction and communication and result in a living continuum
In animal cells:
1. tight junctions- tight together bound by specific proteins. prevents extracellular fluid from permeating the cells. “watertight”. epithelial cells
2. desosomes- function like rivets, anchored by keratin based intermediate filaments, super sturdy. attach muscle to muscle
3. gap junction- function like pores, channels between adjacent cells, allowing communication between tissues