Chapter 6 Flashcards
1
Q
All organisms are made of
A
cells
2
Q
Cells
A
the simplest collection matter that can live
3
Q
Cell Structure
A
the intimately correlated to its function
- i.e. epithelial cell is flat and “plate-like”; functions to create a good barrier
- i.e. fibroblast: “molecular bandaid”
- i.e. neuronal cell is long and branched
4
Q
Microscopy
A
the study cells, biologists use microscopes and the tools of biochemistry
5
Q
Light Microscopes (LM)
A
2 types:
1) Brightfieqld microscopy
2) Fluorescent microscopy
6
Q
Brightfield Microscopy
A
- passes visible light through a specimen and magnifies cellular structures with different types of microscopes, lenses, and dyes
- can look at living cells
- don’t have resolution to look at a specific molecule very carefully
7
Q
Fluorescent Microscopy
A
- shows the locations of specific molecules in the cell by tagging (or highlighting) the molecules with fluorescent dyes or antibodies.
- ## fluorescent substances absorb ultraviolet radiation and emit visible light
8
Q
Electron Microscopes (EM)
A
focus a beam of electrons through a specimen (TEM) or onto its surface (SEM)
9
Q
Scanning Electron Microscope (SEM)
A
- provides for detailed study of the surface of a specimen (cell or tissue)
- i.e. showing that a rabbit trachea is covered with motile organelles called cilia
10
Q
Transmission Electron Microscope (TEM)
A
- provides for detailed study of the internal ultrastructure of cells
- structures inside of a cell
- i.e. profiles a thin section (cut through/cross sections) of tracheal cell revealing untrastructures
11
Q
All cells contain:
A
1) plasma membrane
2) cytosol (semifluid substance/ aqueous environment found in outer membrane)
3) chromosomes (genome)
4) ribosomes (enzyme that synthesizes proteins)
12
Q
Prokaryotic cells
A
-do not contain a nucleus and have their DNA located in an (enriched) region called the nucleoid
- have nucleoid: region of cell that contains the genome, not membrane bound
- cell wall, may have flagella and pili
-i.e. bacteria
13
Q
Eukaryotic cells
A
- internal membranes that compartmentalize their functions, contain a true nucleus bounded by a membranous nuclear envelope
- generally quite a bit bigger than prokaryotic cells
- their internal membranes form organelles (membrane bound)
-i.e. plants
14
Q
Pili
pic
A
attachment structures on the surface of some prokaryotes
15
Q
Nucleoid
pic
A
region where the cell’s DNA is located (not enclosed by a membrane)
16
Q
Ribosomes
pic
A
organelles that synthesize proteins
17
Q
Plasma membrane
pic
A
membrane enclosing the cytoplasm
18
Q
Cell Wall
pic
A
rigid structure outside the plasma membrane
19
Q
Capsule
pic
A
Jelly-like outer coating of many prokaryotes
20
Q
Flagella
pic
A
locomotion organelles of some bacteria
21
Q
Plasma Membrane
A
- lipid bilayer
- functions as a selective barrier and allows sufficient passage of nutrients and waste
- composed of phospholipids and proteins and contains a hydrophobic and hydrophilic regions
22
Q
Plant and animal cells
A
contain most of the same organelles but their extracellular components may be different
23
Q
3 types of unique intercellular junctions in animal cells
A
1) tight junctions
2) desmosomes
3) gap junctions
24
Q
Tight Junctions
A
- anchor cells together along their vertical lines
- proteins that work between the two cells
- form a glue that completely seals the gap between the two cells and does not let anything pass between the two cells
25
Desmosomes
- composed of proteins
| - some proteins that anchor or hold the cells together but let liquid pass through
26
Gap Junctions
- create a direct portal between cells, so liquid can flow through those cells but it cant actually get inside other cells
- switch info from one cell compartment to another
- a way for cell's to communicate
27
Structures in animal cells (not in plant cells)
- Lysosomes
- Centrosomes
- Flagella (in some plant sperm)
28
Structures in plant cells (not in animal cells)
- Chloroplasts
- Central Vacuole and tonoplast
- Cell wall
- Plasmodesmata (similar to gap junctions)
29
Nucleus
houses the genetic instructions of a eukaryotic cell
| -containts most of the genes in the eukaryotic cell and is enclosed by a nuclear envelope
30
Nuclear Envelope
separating the nucleus' contents from the cytoplasm
31
Ribosomes
- function: carry out the protein synthesis (genetic instructions)
- can be found bound to the endoplasmic reticulum (ER) or in the cytosol
- are particles made of ribosomal RNA and protein (hybrid enzyme)
- are composed of 2 major subunits (large and small subunit) (looks like a mushroom)
32
Endomembrane System
-regulates protein traffic and performs metabolic functions in he cell and includes many different structures including: the Endoplasmic Reticulum (ER), Golgi Apparatus, Lysosomes, and Vacuoles
33
Endoplasmic Reticulum (ER)
- adjacent to nucleus
- membrane bound organelle
- membrane is continuous with the nuclear envelope
- composed of two distinct regions: smooth and rough
34
Smooth ER
- lack ribosomes
- function: synthesizes lipids, metabolizes carbohydrates, stores calcium and detoxifies poison
- has enzymes to degrade toxins
35
Rough ER
- contain ribosomes
- function: produces proteins and membranes, which are distributed by transport vesicles
- ribosome can secrete and produce proteins into the lumen (space in between)
- proteins destined to be released outside of the cell will be synthesized in the ER
i.e. insulin
36
Golgi Apparatus
- receives the transport vesicles produced in the rough ER
- consists of flattened membranous sacs called cisternae
- functions: modification of the products of the rough ER (i.e. proteins) and manufacture of certain macromolecules
- receives information on one side, the cis side
- proteins and carbs are moved through the Golgi/ through the cisternae
- leave on the trans side
- "Home Depot" of the cell
- cisternae maturation model
37
cisternae
flattened membranous sacs found in the Golgi apparatus
38
process within the Golgi
1) vesicles move from the ER to the Golgi
2) vesicles coalesce to form new cis Golgi cisternae
3) cisternal maturation
4) vesicles form and leave Golgi, carrying specific proteins to other locations
(trans face: "shipping" side of Golgi apparatus)
5) vesicles transport specific proteins backward to newer Golgi cisternae
6) vesicles also transport certain proteins back to ER
39
Lysosome
- a membranous sac of hydrolytic enzymes that can digest all kinds of macromolecules
- can come off of the Golgi, carry things that can break things down
- carry out intracellular digestion by: phagocytosis or autophagy
40
Phagocytosis
"to eat"
- engulf or ingest with enzymes
- cell will take in some solid molecule; lysosome with "eat" (cell gets nutrients)
i.e. destruction of foreign particles
41
Autophagy
- involves the recycling of damaged organelles by the breakdown of the material with enzymes
- can fuse or merge with a damaged organelle and break it down and recycle it
i.e. breakdown of nucleic acids
42
a plant or fungal cell may have one or several ...
vacuoles
43
Food vacuoles
formed by phagocytosis
44
Contractile vacuoles
pump excess water out of protist cells
| -like a motor
45
Central vacuoles
found in plant cells and hold reserves of important organic compounds (sugar, protein) and water
46
Endomembrane system review
a complex and dynamic player in the eukaryotic cells compartmental organization
1) nuclear envelope is connected to rough ER, which is also continuous with smooth ER (can give rise to vesicles)
2) membranes and proteins produced by the ER flow in the form of transport vesicles to the Golgi
3) Golgi pinches off transport vesicles and other vesicles that give rise to lysosomes and vacuoles
4) lysosome available for fusion with another vesicle for digestion
5) transport vesicle carries proteins to plasma membrane for secretion
6) plasma membrane expands by fusion of vesicles; proteins are secreted from the cell
47
Mitochondria and chloroplasts
change energy from one form to another namely, chemical energy to a form that can be used for cellular work
- plants have both
48
Mitochondria
- found in nearly all eukaryotic cells
- are the sites of cellular respiration and the majority of ATP synthesis
"power-house"
i.e. heart cells have lots of mitochondria
49
Chloroplasts
- found only in plants
- capture light energy (and convert to chemical energy; water, ATP, oxygen) and are the sites of photosynthesis, contain chlorophyll, and are specialized members of a family of closely related plant organelles called plastids
50
Plastids
chloroplasts are specialized members of a family of closely related plant organelles called this
51
Mitochondria structure and function
- enclosed by 2 smooth membranes
- outer membrane and an inner membrane folded into cristae
- sites of cellular respiration and generate ATP from the breakdown of proteins, fats, and sugars
- major source of ATP for the cell
- have their own DNA
52
Chloroplasts structure and function
- have two membranes
- found in leaves and other green organs of plants and in algae
- where photosynthesis happens
- contain their own DNA
- structure includes:
1) Thylakoids: membranous sacs/ form stacks
2) Stroma: the internal fluid contains DNA, ribosomes, and enzymes
- Granum
53
Cytoskeleton
a network of fibers that organizes structures and activates in the cell and extends throughout the cytoplasm
- function: provides mechanical support to the cell and regulates cell motility or movement
- "highway" of the cell
54
Motor proteins
can move along the cytoskeleton and participate in cellular movement, shape change, and contraction
- can stick to cytoskeleton
- grab cargo and move along cytoskeleton
55
Myosin
a motor protein that facilitates muscle contraction and uses ATP
- many diverse functions
- can transport vesicles (cargo)
56
3 main types of fibers that make up the cytoskeleton
1) Microtubules
2) Microfilaments
3) Intermediate filaments
57
Microtubules
- function: shape the cell and guide the movement of organelles
- help separate the chromosomes copies in dividing cells (i.e. mitotic spindle)
- are hollow tubes composed of tubular molecules
- may grow out of the centrosome
- composed of protein tubulin
58
Centrosome
located near the nucleus and is considered to be a "microtubule-organizing center"
- contains a pair of centrioles
- helps produce microtubules
59
Centrioles
composed of 9 sets of triplet microtubules arranging in a ring
-help "pull" cells apart
60
Cilia and Flagella
- contain specialized arrangements of microtubules
- are locomotor appendages of some cells
- may provide cellular movement or propulsion by beating or undulating ("whip")
- can extend from a tissue layer to move fluid over the surface of the tissue
- microtubules can be found in these
i.e. cilia lining the airways move debris out of the lungs
61
Dynein
```
a protein (enzyme) that is responsible for causing cilia and flagella to move
-cause molecular motion
```
62
Cilia and flagella structure
share a common ultrastructure
- microtubules arranged in a symmetric ring
- contain a central pair of microtubules
- are enclosed by a membrane
63
Microfilaments
- composed of protein actin
- built from molecules of the protein actin and are found in microvilli
- twisted chains of actin proteins that provide support (and shape) and help bear tension
64
Microfilament function
- function in cellular motility
| - contain the motor protein myosin that can walk along actin filaments
65
Myosin motors
move along actin filaments causing cellular (muscle) contraction, amoeboid movement, or cytoplasmic streaming in plants
66
Plant extracellular structures
contain cellulose and proteins that are different than extracellular animal structures
67
Extracellular Matrix (ECM)
- lack cell walls and are covered by an elaborate matrix
| - made up of glycoproteins and other macromolecules
68
ECM functions
1) Support: help hold cell in place
2) Adhesion: allow cell to adhere to a particular location
3) Movement: extend processes and (attaching itself) move itself along the ECM
69
Cells rely on...
the integration of structures and organelles in order to function
- cell is a living unit that is greater than the sum of its parts
i. e. phagocytic immune cells (white blood cells) ingest infectious bacteria
