The Cell Flashcards
1
Q
cell (defn)
A
basic fundamental unit of all living things.
2
Q
plasma membrane (cell membrane) (defn)
A
bounds the cell and encloses the nucleus and cytoplasm; phospholipid bilayer.
3
Q
cytoplasm (defn)
A
consists of specialized bodies called organelles and cytosol; fluid matrix consisting of water and dissolved substances such as proteins and nutrients.
4
Q
peripheral proteins (defn)
A
proteins that attach loosely to the inner or outer surfaces of the membrane.
5
Q
integral proteins (defn)
A
proteins that extend to the interior of the phospholipid bilayer.
6
Q
transmembrane proteins (defn)
A
proteins that span across the membrane and appear at both of the outer surfaces.
7
Q
amphipathic (defn)
A
both hydrophilic and hydrophobic (ex. phospholipid bilayer)
8
Q
fluid mosaic model (defn)
A
term describing characteristic of environment like the plasma membrane that has scattered proteins and cytosol that is a fluid matrix.
9
Q
phospholipid bilayer/membrane (2)
A
- selectively permeable
- small, uncharged, polar molecules (ex. H2O, CO2) and nonpolar hydrophobic molecules (O2) can pass; large molecules (glucose) and charged species (Na+, Cl-, K+) cannot freely pass.
10
Q
Types of molecules that can pass through the phospholipid bilayer are ____, ______, ______ molecules (ex. ___, ___ ) and ________, _____________ molecules (ex. __ ).
Types of molecules that cannot pass freely are ______ molecules (ex. ________ ) and _______ species (ex. ___, ___, ___)
A
small, polar, uncharged (H2O, CO2)
uncharged, hydrophobic (O2)
large (glucose)
charged (Na+, Cl-, K+)
11
Q
Types of proteins (8)
A
- Channel proteins
- Ion channels
- Porins
- Carrier proteins
- Transport proteins
- Recognition proteins
- Adhesion proteins
- Receptor proteins
12
Q
Channel protein
A
provides open passageway to hydrophilic molecules.
13
Q
Ion channels
A
allow the passage of ions.
In muscle and nerve cells, ions are called gated channels and respond to certain stimuli to allow passage of specific ions (Na+, K+).
14
Q
Gated channels
A
ion channels of the nerve and muscle cells that respond to certain stimuli to allow passage of specific ions (Na+, K+).
15
Q
Porins
A
allow passage of certain ions and small polar molecules (ex. aquaporin).
16
Q
Aquaporins
A
found in the plasma membrane of certain cells, specifically of the kidneys and plant roots, that dramatically increase the rate of H2O passage.
17
Q
Carrier proteins
A
bind to specific molecules and go through conformational change then transfer molecule across the membrane (ex. glucose carrier protein).
18
Q
Transport proteins
A
use energy (ATP) to transfer molecules across the membrane. The process is called “active” transport because it uses energy. (ex. Na+-K+ antiporter pump).
19
Q
Recognition proteins
A
glycoproteins with short polysaccharide chains attached that give each cell a unique identification; provides distinction between cells (self cells vs. foreign cells).
20
Q
Recognition proteins are ____proteins with short _____________ _______.
A
glycoproteins
polysaccharide chains
21
Q
Adhesion proteins
A
attach cells to neighboring cells or provide anchors for internal filaments or tubules that give stability to the cell.
22
Q
Receptor proteins
A
provide binding sites for hormones or trigger molecules
23
Q
Cholesterol (also part of plasma membrane)
A
provides rigidity to plasma membrane of animal cells. In plants, sterols provide rigidity to plant’s plasma membrane.
24
Q
Cholesterol provides rigidity to plasma membrane of _______ cells. Plant cells have _____ that provide rigidity to their plasma membrane.
A
animal
sterols
25
Glycocalx
on the surfaces of bacteria cell walls and some animal cell membranes; consists of glycolipids or glycoproteins; provide adhesive capabilities, barrier to infection, and markers for cell-to-cell recognition.
26
_______ are on the surfaces of bacteria cell walls and some animal membranes. They consist of _______ or ______ and have three functions (3).
```
Glycocalx
glycoproteins or glycolipids
1. provide adhesive capabilities
2. barrier to infection
3. marker for cell-to-cell recognition.
```
27
Nucleus (4)
1. bound by nuclear envelope consisting of two phospholipid bilayers
2. contains DNA as chromatin, then chromosome during replication
3. nucleosomes are coiled DNA with histones
4. nucleoli is concentration of DNA in process of manufacturing ribosomes
28
Nucleosomes are ______ DNA with ______.
| Nucleoli is _________ DNA in the process of manufacturing _________.
coiled; histones
| concentrated; ribosomes.
29
Ribosomes
subunits that are assembled in the nucleoli and consist of RNA and proteins. They are 60S and 40S in the nucleus and become 80S in the cytoplasm. In the cytoplasm they assist in amino acid to protein translation.
30
Endoplasmic Reticulum
flattened sacs involved in production of various materials. Rough ER creates glycoproteins. Smooth ER creates lipids and hormones. The liver cell's smooth ER breaks down toxins, drugs, and toxic byproducts from cellular respiration.
31
Rough endoplasmic reticulum create __________. Smooth endoplasmic reticulum create ________ and ______.
glycoproteins
| lipids and hormones
32
Golgi Apparatus
flattened sacs that package lipids and proteins into vesicles
33
Lysosomes
vesicles from the Golgi Apparatus that contain digestive enzymes; break down food, cellular debris, and foreign invaders such as bacteria; low pH is maintained in lysosomes that is favorable for digestive enzymes.
34
Peroxisomes
break down hydrogen peroxide (H2O2 -> H2O + O2), fatty acids, amino acids. Common in liver and kidney cells. In plant cells peroxisomes modify byproducts of photorespiration and in germinating seeds, gloxysomes break down stored fatty acids to help generate energy for growth.
35
Peroxisomes break down ________ ________, ______ ______, and _______ ______ into water and oxygen. They are common in the ______ and ______ cells. In plant cells peroxisomes modify byproducts of ________. In germinating seeds, __________ break down stored fatty acids to help generate ______ for growth.
hydrogen peroxide, fatty acids, amino acids
liver and kidney
photorespiration
glyoxysomes; energy
36
Mitochondria
carry out aerobic respiration; ATP is obtained from carbohydrates.
37
Mitochondria carry out ________ _________.
aerobic respiration
38
Chloroplasts
carry out photosynthesis, energy from sunlight transformed to carbs.
39
Microtubules, intermediate filaments, microfilaments
protein fibers that decrease in size of width, respectively.
40
Microtubules
made from tubulin, provide support and motility for cellular activities; found in spindle apparatus during cell division and flagella and cilia.
41
Intermediate filaments
provide support for maintaining shape of cell.
42
Microfilaments
made from protein actin and involved in cell mobility; found in muscle cells and cells that move by changing shape such as phagocytes (WBCs).
43
Flagella and cilia
provide mobility; made of microtubules arranged in 9+2 circular pattern with 2 in the center and 9 pairs forming the outline of the circle.
44
Centrioles and Basal Bodies
centrioles enclosed in the centrosomes hold microtubules that make up the spindle fibers of cell division; basal bodies develop cilia and flagella.
45
Centrioles are enclosed in the ____________ and hold _____________ that make up the __________ _______ during cell division. Basal bodies develop _________ and ______.
centrosomes; microtubules; spindle fibers
| cilia and flagella
46
Vacuoles and vesicles (defn + 5 types)
fluid-filled, membrane-bound bodies.
1. transport vesicles
2. food vacuoles
3. storage vacuoles
4. central vacuoles
5. contractile vacuoles
47
Transport vesicles
move materials between organelles or organelles and plasma membrane
48
Food vacuoles
temporary receptacles for nutrients; merge with lysosome to break down food
49
Storage vacuoles
plants store starch, pigment, toxic substances
50
Central vacuoles
large bodies occupying most of plant cell; contributes to turgor pressure that is exerted when full. It maintains the cell shape; also stores nutrients and have lysosome-like functions (plant cells don't have lysosomes).
51
Central vacuoles are in the _____ cell. It contributes to _______ pressure that is exerted when full and helps to maintain cell shape. It also stores ______ and has functions similar to _________ which are missing in _____ cells.
plant; Turgor; nutrients; lysosomes; plant
52
Contractile vacuoles
in single-celled organisms that collect and pump excess water out of the cell.
53
Single-celled organisms have _________ vacuoles that collect and pump excess _______ out of the cell.
contractile; water
54
Cell walls (5)
1. found in plants, fungi, protists, bacteria
2. develop outside the plasma membrane and provide support for the cell
3. In plants, it is composed of cellulose
4. In fungi, it is composed of cellulose and chitin
5. In bacteria, it is composed of peptidoglycan
55
The cell wall of plants is composed of __________.
The cell wall of fungi is composed of _________ and ______.
The cell wall of bacteria is composed of ____________.
cellulose
cellulose; chitin
peptidoglycan
56
Extracellular matrix (4)
1. found in animal cells
2. found in areas between adjacent cells that is occupied by fibrous structural proteins, adhesion proteins, and polysaccharides secreted by the cells
3. provides mechanical support and helps bind adjacent cells together
4. most common substance is collagen
57
The most common substance of the extracellular matrix is ______ and its location between two adjacent cells is occupied by ________ ________ _______, _______ ______, and ________________.
collagen
| fibrous structural proteins; adhesion proteins; polysaccharides secreted by the cells.
58
Cell Junctions (defn + 3 types)
serve to anchor cells and provide passageway for cellular exchange
1. anchoring junctions
2. tight junctions
3. communicating junctions
59
Anchoring junctions
protein attachments between animal cells; example is desmosome which made up of keratin and protein filaments that extend into the interior of the cell and serve to hold cellular structures together.
60
Desmosome is an example of an __________ ________ and is made up of _______ and ________ ___________ that extend into the interior of the cell and functions to ___________________.
anchoring junction; keratin; protein filaments; hold cellular structures together.
61
Tight junctions
tightly stitched seams between animal cells; the junction prevents passage of materials between the cells (keep materials within interior of cells and prevent escape to extracellular region); found in cells lining the digestive tract.
62
Tight junctions are found only in ______ cells. Its function is to ________________________________. They are found in the cells lining the _________ ______.
animal
prevent passage of materials between the cells and keep materials within the interior of the cells to prevent escape to the extracellular region
digestive tract
63
Communicating junctions (defn + 2 types)
passageways between cells that allow transfer of chemical or electrical signals
1. Gap junctions
2. Plasmodesmata
64
Gap junctions
narrow tunnels between animal cells and consist of proteins called connexins; allow passage of ions and small molecules; channel proteins two adjacent cells that are closely aligned.
65
Connexins are the proteins that are in _____ junctions, which are junctions that allow passage of ____ and ____ molecules and are basically two closely aligned _______ proteins from each adjacent cell that.
gap; ions and small molecules; channel
66
Plasmodesmata
narrow channels between plant cells; narrow tubule of endoplasmic reticulum called desmotubules pass through the plasmodesmata channel. Material exchange occurs in the plasmodesmata but outside of the desmotubules.
67
Desmotubules
narrow tubules that spring from the endoplasmic reticulum and spans across two ERs of the connected cells.
68
Plant cell differences:
1. Plant cells have unique to them ____ ____, _________, ________ _________.
2. Plant cells lack _________, _________, _________.
cell wall, chloroplasts, central vacuole
| lysosomes, centrioles, cholesterol
69
Three organelles that are unique to plants are...
cell wall, chloroplasts, and central vacuole.
70
Three organelles that plant cells lack are...
lysosomes, centrioles, cholesterol
71
Differences between Prokaryotes and Eukaryotes (6)
1. prokaryotes consist of only plasma membrane, ribosome, one DNA molecules (chromatid), cytoplasm, cell wall
2. prokaryotes don't have nucleus
3. DNA is a single, naked strand without proteins such as histones
4. prokaryotic ribosomes are smaller in size (50S, 30S, 70S)
5. Cell walls of bacteria and cyanobacteria are made up of peptidoglycan
6. Prokaryotic flagella is not constructed by microtubules.
72
Differences between Proks and Euks:
1. Proks consist of only of these five organelles:
2. Proks do not have a _______.
3. Prok DNA is a _____, _____ strand without proteins such as _______.
4. Prok ribosomes are _________ in size.
5. Cell walls of bacteria and cyanobacteria are composed of ____________.
6. Prok flagella is/isn't constructed by microtubules.
1. cell wall, single DNA strand (chromatid), ribosomes, cytoplasm, plasma membrane.
2. a nucleus
3. single, naked; histones
4. smaller
5. peptidoglycan
6. isn't
73
Five facts about the movement of substances in cells
1. selective permeable membrane such as a plasma membrane allow passage of specific substances
2. water is a solvent, substance dissolved in water is the solute.
3. movement can be with or against the concentration gradient.
4. hypertonic solution is when the concentration of the solute is high; hypotonic solution is when the concentration of the solute is low and the concentration of water is high; isotonic solution is when there is an equal concentration of solutes.
5. passive, active movements - active needs energy.
74
1. ___________ __________ ____________ like the plasma membrane allow passage of ______ _______.
2. Water is a ____ and substances dissolved in water is a _____.
3. Movement can be with or against the __________ _______.
4. Hypertonic, Hypotonic, Isotonic
5. There are _______ and ________ movements and the _______ movement needs energy.
1. specific substances
2. solvent; solute
3. concentration gradient
4. hypertonic - high solute concentration; hypotonic - low solute concentration, high water concentration; isotonic - equal solute concentration
5. passive and active; active
75
Bulk flow
collective movement of substances in the same direction in response to force or pressure (ex. blood through blood vessels)
76
Passive transport (defn + 6 types)
movement down the concentration gradient (high->low); no energy required.
1. Simple diffusion
2. Osmosis
3. Dialysis
4. Plasmolysis
5. Facilitated diffusion
6. Countercurrent Exchange
77
Simple diffusion
net movement of substances from [high] to [low]
78
Osmosis
diffusion of water across the selectively permeable membrane
79
Dialysis
diffusion of solutes across the selectively permeable membrane; different solutes are separated by the selectively permeable membrane
80
Plasmodysis
movement of water as a result of cell collapse
81
Facilitated diffusion
with channel proteins like aquaporins to increase the rate of diffusion of water and solutes.
82
Countercurrent exchange
diffusion of substances between two regions in which substances are moving by bulk flow in opposite directions.
83
Active transport
movement of solutes against the concentration gradient and requires energy; usually ATP. Transport proteins are commonly used.
84
Vesicular transport
uses vesicles or other bodies in the cytoplasm to move macromolecules or large particles across the plasma membrane.
85
Exocytosis
describes process of vesicles fusing with the plasma membrane and releasing contents to the outside of the cell
86
Endocytosis (defn + 3 types)
capture of substances outside the cell with plasma membrane engulfing them.
1. phagocytosis
2. pinocytosis
3. receptor-mediated endocytosis
87
Phagocytosis
undissolved materials enter the cell; can attack bacteria and foreign invaders
88
Pinocytosis
dissolved substances enter cell; plasma membrane folds to form channel to let liquid enter. The channel becomes a vesicle.
89
Receptor-Mediated Endocytosis
specific molecules in fluid surround the cell and bind by ligands to receptor (ex. proteins that transport cholesterol in blood and certain hormones target specific cells by receptor-mediated endocytosis).
