Homeostasis and Cells Flashcards
1
Q
All cells arise from _______________ in which one cell divides into _______________
A
existing cells; two identical cells
2
Q
The average adult human body consists of more
than
A
100 trillion cells
3
Q
are the basic, living, structural, and functional units of the body
A
Cells
4
Q
The scientific study of cells is called
A
cell biology or cytology
5
Q
-first lenses used in Europe
-used to determine cloth quality (weave and precision)
-combos of lenses gave better view
A
Late 1500’s
6
Q
Leeuwenhoek uses microscope to study nature
A
Early 1600’s
7
Q
uses microscope to study nature
A
Leeuwenhoek
8
Q
first to view pond water organisms
A
Leeuwenhoek
9
Q
First to see living microscopic organisms
A
Leeuwenhoek
10
Q
*Leeuwenhoek
*first to view pond water
organisms
*First to see living
Microscopic organisms
*Made careful sketches
A
Early 1600’s
11
Q
Anton van Leeuwenhoek in _____________
- Used a handmade microscope to observe pond
scum & discovered single-celled organisms
A
1673
12
Q
Used a handmade microscope to observe pond scum & discovered single-celled organisms
A
Anton van Leeuwenhoek
13
Q
Anton van Leeuwenhoek in 1673 used a handmade microscope to observe pond scum & ______________________________
A
discovered single-celled organisms
14
Q
Anton van Leeuwenhoek used a handmade microscope to observe pond scum & discovered single-celled organisms and called them
A
animalcules
15
Q
*He also observed blood cells from fish, birds, frogs, dogs, and humans
* Therefore, it was known that cells are found in animals as well as plants
A
Anton van Leeuwenhoek
16
Q
Used light microscope to look at thin slices of plant tissues – cork
A
Robert Hooke ( 1665)
17
Q
Looked empty, like monk’s chamber
Called tiny chambers
A
cells
18
Q
*German Botanist (plants)
*All plants looked at were made of cells, so concluded:
*“All plants are made of cells.”
A
Matthias Schleiden 1838
19
Q
- German scientist who studied animals – zoologist
*Saw that all animals he studied were cellular so concluded:
*“All animals are made of cells.”
A
Theodore Schwann – 1839
20
Q
*German physician who studied cell reproduction
*“Where a cell exists, there must have been a preexisting cell…..”
A
Rudolf Virchow – 1855
21
Q
Discovery of cell (Timeline)
A
*Robert Hooke (mid-1600s) : CELL
*Robert Brown (1831) : NUCLEUS
*Johannes Purkinje (1830s) : PROTOPLASM
*Theodor Schwann & Matthias Schleiden (1839)
*Rudolf Virchow (1855)
22
Q
The Cell Theory
A
- All living things are composed of cells
- Cells are the basic units of structure and function in living things
- New cells are produced from existing cells
23
Q
Parts of a cell 9that can be seen in a compund microscope)
A
Plasma membrane
Cytoplasm
Nucleus
24
Q
forms the cell’s flexible outer surface, separating the cell’s internal environment (everything inside the cell) from the
external environment (everything outside the cell).
A
Plasma membrane
25
consists of all the cellular contents between the plasma
membrane and the nucleus.
Cytoplasm
26
Cytoplasm has two components
cytosol and organelles
27
is a large organelle that houses most of a cell’s DNA.
Nucleus
28
Within the nucleus, each chromosome, a single molecule of DNA associated with several proteins, contains thousands of hereditary units called _________ that control most
aspects of cellular structure and function.
genes
29
The plasma membrane, a flexible yet sturdy barrier that
surrounds and contains the cytoplasm of a cell, is best
described by using a structural model called the
fluid mosaic model
30
is the basic structural framework of the plasma
membrane
Lipid Bilayer
31
Lipid Bilayer is made up of 3 types of lipid molecules
- 75% - phospholipids (lipids that contain phosphorus)
- 20% - cholesterol (a steroid with an attached -OH (hydroxyl) group)
- 5% - glycolipids (lipids with attached carbohydrate groups)
32
What is the polar part in phospholipids?
phosphate containing “head,” which is hydrophilic
33
hydro
water
34
philic
loving
35
What are the non-polar part in phospholipids?
2 long fatty acid “tails,” which are hydrophobic hydrocarbon
chains.
36
Arrangement of Membrane Proteins:
Integral proteins and Peripheral proteins
36
extend into or through the lipid bilayer and are
firmly embedded in it
Integral proteins
37
Most integral proteins are _________________, which means that they span the entire lipid bilayer and protrude into both the cytosol and extracellular fluid.
transmembrane proteins
38
they span the entire lipid bilayer and protrude into both the cytosol and extracellular fluid
transmembrane proteins
39
are not as firmly embedded in the membrane.
Peripheral proteins
40
They are attached to the polar heads of membrane lipids or to integral proteins at the inner or outer surface of the membrane.
Peripheral proteins
41
Many integral proteins are _______________ with carbohydrate groups attached to the ends that protrude into the extracellular fluid.
glycoproteins
42
proteins with carbohydrate groups attached to the ends that protrude into the extracellular fluid.
glycoproteins
43
Carbohydrates are ____________________
oligosaccharides
44
oligo
few
45
saccharides
sugars
46
chains of 2 to 60 monosaccharides that may be straight or
branched
carbohydrates/oligosaccharides
47
The carbohydrate portions of glycolipids and glycoproteins form an extensive sugary coat called the
glycocalyx
48
The pattern of carbohydrates in the glycocalyx __________________________________________________
varies from one cell to another
49
Functions of the Plasma Membrane
1. Acts as a barrier separating inside and outside of the cell.
2. Controls the flow of substances into and out of the cell.
3. Helps identify the cell to other cells (e.g., immune cells).
4. Participates in intercellular signaling.
50
are fluid structures because the lipids and many of the proteins are free to rotate and move sideways in their own half of the bilayer.
Membranes
51
largely reflect the functions a cell can perform.
Membrane proteins
52
Forms a pore through which a specific ion can flow to get
across membrane. Most plasma membranes include
specific channels for several common ions.
lon channel (integral)
53
transports a specific substance across membrane by undergoing a change in shape. For example, amino acids, needed to synthesize new proteins, enter the body via carriers
carrier (integral)
54
Carrier proteins are also known as
transporters
55
Recognizes specific ligand and alters cell's function in
some way. For example, antidiuretic hormone binds
to receptors in the kidneys and changes the water permeability of certain plasma membranes
Receptor (integral)
56
Catalyzes reaction inside or outside cell (depending on
which direction the active site faces). For example lactase protruding from epithelial cells lining your small intestine splits the disaccharide lactose in the milk you drink.
Enzyme (integral and peripheral)
57
Anchors filaments inside and outside the plasma
membrane, providing structural stability and shape for the cell. May also participate in movement of the cell or link two cells together.
Linker (integral and peripheral)
58
Distinguishes your cells from anyone else's (unless you are an identical twin). An important class of such markers are the major histocompatibility (MHC) proteins
Cell identity marker (glycoprotein)
59
MHC means
major histocompatibility
60
Membranes are _____________________; that is, most of the membrane lipids and many of the membrane proteins easily rotate and move sideways in their own half of the bilayer
fluid structures
61
means that a structure permits the passage of substances through it
permeable
62
means that a structure does not permit the passage of substances through it
impermeable
63
Membranes are fluid structures; that is, most of the membrane lipids and many of the membrane proteins easily
rotate and move sideways in their own half of the bilayer
64
of the plasma membrane to different substances
varies.
permeability
65
Plasma membranes permit some substances to pass more
readily than others. This property of membranes is termed
selective permeability
66
membrane proteins can be structurized according to:
Structure and Function
67
For Structure Membrane Proteins (2) :
Integral and Peripheral Proteins
68
For Function Membrane Proteins (4):
Membrane Transporters
Structural Proteins
Membrane Enzymes
Membrane Receptors
69
Types of Membrane Transport Proteins
Carrier proteins
Channel proteins
70
Channel Proteins form
Open Channels and Gated Channels
71
Types of gated channels
Mechanically gated channel
Voltage-gated channel
Chemically-gated channel
72
Structural Proteins are found in
Cell junctions and cytoskeleton
73
Membrane enzymes are active in
metabolism and signal transfer
74
membrane receptors activate
membrane enzymes
75
membrane receptors are active in
receptor-mediated endocytosis and signal transfer
76
membrane receptors open and close
chemically gated channel
77
embedded in lipid bilayer
Transport Proteins
78
channel for lipid insoluble molecules and ions to pass freely through
Channel Proteins
79
bind to a substance and carry it across membrane, change shape in process
Carrier Proteins
80
create a water-filled pore
channel proteins
81
open and close in response to signals
gated channels
82
or pores are usually open
open channels
83
never form an open channel between the two sides of the membrane
carrier proteins
84
carrier proteins can be classified as
uniport carriers, symport carriers, antiport carriers
85
cotransporters
symport carriers and antiport carriers
86
Substance Permeability Across Membrane
Few molecules move freely: Water, Carbon dioxide, Ammonia, Oxygen
87
uses energy of molecular motion. does not require ATP
Diffusion
88
Requires energy from ATP
primary and secondary active transport, endocytosis, exocytosis, phagocytosis
89
2 types of diffusion
simple diffusion and facilitated diffusion
90
primary active transport creates concentration gradient for
secondary active transport
91
uses a membrane-bound vesicle
endocytosis, exocytosis, phagocytosis
92
mediated transport requires a membrane protein
secondary active transport
93
molecules goes through lipid bilayer
simple diffusion
94
a substance moves down its concentration or electrical gradient to cross the membrane using only its own kinetic energy (energy of motion).
Passive processes
95
Types of Passive Transport
1. Diffusion
2. Osmosis
3. Facilitated diffusion
96
molecules move to equalize concentration
Diffusion
97
- Special form of diffusion; Fluid flows from lower solute concentration to higher solute concentration
- Often involves movement of water: Into cell/Out of cell
Osmosis
98
solvent + solute =
solution
99
– Solutes in cell more than outside
– Outside solvent will flow into cell
Hypotonic
100
– Solutes equal inside & out of cell
Isotonic
101
– Solutes greater outside cell
– Fluid will flow out of cell
Hypertonic
102
is a specific type of diffusion; it is the passage of water from a region of high water concentration through a semi permeable membrane to a region of low water concentration.
Osmosis
103
- Channels (are specific) help molecule or ions enter or leave the cell
- Channels usually are transport proteins (aquaporins facilitate the movement of water)
- No energy is used
Facilitated Diffusion
104
How Facilitated Diffusion works
1. Protein binds with molecule
2. Shape of protein changes
3. Molecule moves across membrane
105
movement of water and solute molecules across the cell membrane due to hydrostatic pressure generated by the cardiovascular system
Filtration
106
Molecular movement requires energy (against gradient)
Active Transport
107
Example of active transport is
sodium-potassium pump
108
process of sodium-potassium pump
The sodium-potassium pump system moves sodium and potassium ions against large concentration gradients. It moves two potassium ions into the cell where potassium levels are high, and pumps three sodium ions out of the cell and into the extracellular fluid.
Three sodium ions bind with the protein pump inside the cell. The carrier protein then gets energy from ATP and changes shape. In doing so, it pumps the three sodium ions out of the cell. At that point, two potassium ions from outside the cell bind to the protein pump. The potassium ions are then transported into the cell, and the process repeats. The sodium-potassium pump is found in the plasma membrane of almost every human cell and is common to all cellular life. It helps maintain cell potential and regulates cellular volume.
109
Movement of Phagocytosis is
To the ICF
110
Vesicles of Phagocytosis is
Large membrane bound vesicle
111
Function of Phagocytosis is
engulfs a bacterium or other particle
112
Mechanism of Phagocytosis is
phagosome pinches off from the cell membrane
113
Movement of Endocytosis is
To the ICF
114
Vesicles of Endocytosis is
Smaller vesicles
114
Function of Endocytosis is
To move large molecules or particles into cells
115
Mechanism of Endocytosis is
membrane surface indents, could be nonselective or receptor mediated
116
Movement of Exocytosis is
To the ECF
117
Vesicles of Exocytosis is
Intracellular vesicles
118
Function of Exocytosis is
export large lipophobic molecules, (proteins), get rid of wastes left in lysosomes, insert proteins into the cell membrane
119
Mechanism of Exocytosis is
Rabs, help vesicles dock onto the membrane, & SNAREs, which facilitate membrane fusion
120
* Movement of large material
- Particles
- Organisms
- Large molecules
* Movement is into cells
Endocytosis
121
Types of endocytosis
- bulk-phase (nonspecific)
- receptor-mediated (specific)
122
Process of Endocytosis
1. Plasma membrane surrounds material
2. Edges of membrane meet
3. Membranes fuse to form vesicle
123
Forms of Endocytosis
Phagocytosis and Pinocytosis
124
cell eating
Phagocytosis
125
cell drinking
Pinocytosis
126
- Reverse of endocytosis
- Cell discharges material
Exocytosis
127
Process of Exocytosis
1. Vesicle moves to cell surface
2. Membrane of vesicle fuses
3. Materials expelled
128
What are the 3 parts of the cell that can be seen under a compound microscope?
Nucleus, Plasma Membrane, Cytoplasm
129
all the cellular contents within the plasma membrane except for the nucleus—consists of
cytosol and organelles
130
—all the cellular contents within the plasma membrane except for the nucleus—consists of cytosol and organelles.
Cytoplasm
131
is the fluid portion of cytoplasm, containing water, ions, glucose, amino acids, fatty acids, proteins, lipids, ATP, and waste products
Cytosol
132
It is the site of many chemical reactions required for a cell’s existence
Cytosol
133
are specialized structures with characteristic shapes that have specific functions
Organelles
134
- is a network of protein filaments that extends throughout the cytosol
Cytoskeleton
135
are the thinnest elements of the cytoskeleton
Microfilaments
136
proteins in microfilament
actin and myosin
137
They help generate movement and provide mechanical support.
Microfilaments
138
are thicker than microfilaments but thinner than microtubules
Intermediate filaments
139
the largest of the cytoskeletal components, are long, unbranched hollow tubes composed mainly of the
protein tubulin.
Microtubules
140
The assembly of microtubules begins in an organelle called the
centrosome
141
Function of Cytoskeleton
1. Serves as a scaffold that helps determine a cell’s shape
and organize the cellular contents.
2. Aids movement of organelles within the cell, of
chromosomes during cell division, and of whole cells such
as phagocytes.
142
are specialized structures within the cell that have characteristic shapes, and they perform specific functions in cellular growth, maintenance, and reproduction
Organelles
143
What structure of the cell which has a pair of centrioles and the pericentriolar matrix?
centrosome
144
microtubule organizing center
Centrosome
145
Centrosome (microtubule organizing center), is located near the nucleus, consists of two components:
a pair of centrioles and the pericentriolar matrix
146
Functions of the Centrosomes
1. The pericentriolar matrix of the centrosome contains tubulins that build microtubules in nondividing cells.
2. The centriols of the centrosome forms the mitotic spindle during cell division.
147
are cylindrical structures, each composed of nine
clusters of three microtubules (triplets) arranged in a circular pattern
Centrioles
148
Surrounding the centrioles is the _____________________, which contains hundreds of ring-shaped complexes composed of the protein tubulin
pericentriolar matrix
149
forms the mitotic spindle during cell division
centrioles
150
- are numerous, short, hairlike projections that extend from the surface of the cell
- Each contains 20 microtubules
Cilia
151
Each is anchored to a basal body just below the surface of the plasma membrane
Cilia
152
Each cilia is anchored to a _______________ just below the surface of the plasma membrane
basal body
153
singular of cilia is
cilium
154
- are similar in structure to cilia but are typically much longer
- Usually move an entire cell
Flagella
155
Generates forward motion along its axis by rapidly wiggling in a wavelike pattern.
Flagella
156
It is the only example of a flagellum in the human body
sperm
157
What is the functional difference between cilia and flagella?
The motion of cilia is rotational, very fast moving. The motion of flagella is rotary movement in prokaryotes whereas it is bending movement in eukaryotes.
158
The site of protein synthesis is?
Ribosomes
159
The name of these tiny structures (ribosomes) reflects their high content of one type of ribonucleic acid (ribosomal RNA, or rRNA), but each ribosome also includes more than
50 proteins
160
Structurally, a ribosome consists of two subunits, one about half the size of the other. What are these subunits?
large and small subunits
161
Where are subunits of ribosomes synthesized and assembled?
nucleolus
162
is a network of membranes in the form of flattened sacs or tubules
Endoplasmic Reticulum
163
is continuous with the nuclear membrane and is usually folded into flattened sacs.
Rough ER
164
In some cases, enzymes attach the proteins to carbohydrates to form
glycoproteins
165
In other cases, enzymes attach the proteins to phospholipids, also synthesized by
rough ER
166
These molecules may be incorporated into the membranes of organelles, inserted into the plasma membrane, or secreted via exocytosis.
glycoproteins and phospholipids
167
produces secretory proteins, membrane proteins, and many organellar proteins
rough ER
168
extends from the rough ER to form a network of membrane tubules
Smooth ER
169
does not have ribosomes on the outer surfaces of its membrane
Smooth ER
170
contains unique enzymes that make it functionally more diverse than rough ER
Smooth ER
171
Because it lacks ribosomes, smooth ER does not synthesize proteins, but it does synthesize ________________________________________, such as estrogens
and testosterone.
fatty acids and steroids
172
However, smooth ER contains unique enzymes that make it
functionally more diverse than rough ER. Because it lacks
ribosomes, smooth ER does not synthesize proteins, but it
does synthesize fatty acids and steroids, such as
estrogens and testosterone
173
It consists of 3 to 20 cisterns (sis-TER-nē = cavities; singular is cistern), small, flattened membranous sacs with bulging edge.
* Golgi complex
174
(cis) face is a cistern that faces the rough ER
Convex entry
175
(trans)face is a cistern that faces the plasma membrane
Concave exit
176
Sacs between the entry and exit faces are called
medial cisterns
177
What are the three general destinations for proteins that leave the Golgi complex?
lysosomes, the plasma membrane, or secretion
178
Often referred to as the "digestive organelles" of the cell
Lysosomes
179
are membrane-enclosed vesicles that form from the
Golgi complex
Lysosomes
180
Contains as many as 60 kinds of powerful digestive and
hydrolytic enzymes that can break down a wide variety of
molecules once lysosomes fuse with vesicles formed during
endocytosis
181
also help recycle worn-out cell structures
Lysosomal enzymes
182
The process by which entire worn-out organelles are digested is called
autophagy
183
The organelle to be digested is enclosed by a membrane derived from the ER to create a vesicle called an
autophagosome
184
is also involved in cellular differentiation, control of growth, tissue re-modeling, adaptation to adverse environments, and cell defense
autophagy
185
may also destroy the entire cell that contains them, a process known as autolysis
Lysosomal enzymes
186
Lysosomal enzymes may also destroy the entire cell that
contains them, a process known as
autolysis.
187
Another group of organelles similar in structure to lysosomes, but smaller, are the
peroxisomes
188
Peroxisomes are also called
microbodies
189
Peroxisomes contain several ___________________, enzymes that can oxidize (remove hydrogen atoms from) various organic substances
oxidases
190
in peroxisomes oxidize toxic substances, such as alcohol
Enzymes
191
peroxisomes are very abundant in the _____________, where
detoxification of alcohol and other damaging substances occurs
liver
192
Mitochondria generate most of the ATP through ____________________
aerobic (oxygen-requiring) respiration
193
are referred to as the “powerhouses” of the cell
Mitochondria
194
A cell may have as few as a _____________ or as many as
________________ mitochondria, depending on its
activity.
hundred; several thousand
195
are usually located within the cell where oxygen enters the cell or where the ATP is used.
Mitochondria
196
contains a series of folds called mitochondrial cristae
Internal mitochondrial membrane
197
The Internal mitochondrial membrane contains a series of folds called
mitochondrial cristae
198
The central fluid-filled cavity of a mitochondrion, enclosed by the internal mitochondrial membrane, is the
mitochondrial matrix
199
a spherical or oval-shaped structure that usually is the most prominent feature of a cell
nucleus
200
“Control Center”
nucleus
201
Within the nucleus are most of the cell’s hereditary units, called _______ which control cellular structure and direct cellular activities
genes
202
is a long molecule of DNA that is coiled together with several proteins
chromosome
203
This complex of DNA, proteins, and some RNA is called
chromatin
204
The total genetic information carried in a cell or an organism is its
genome
205
Electron micrographs reveal that chromatin has a
beads-on-astring structure
206
Each bead is a nucleosome that consists of double-stranded DNA wrapped twice around a core of eight proteins called
histone
207
help organize the coiling and folding of DNA
histone
208
Just before cell division takes place, however, the DNA replicates (duplicates) and the loops condense even more, forming a pair of
chromatids
209
210
forms a pore through which a specific ion can flow to get across membrane
ion channel (integral)
