Exam #2 Review Flashcards
1
Q
What can be seen with light microscopy?
A
whole cells, nuclei, large mitochondria, chloroplasts, vacuoles
2
Q
What can be seen with electron microscopy?
A
ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, cell membranes, and detailed structures within organelles
3
Q
Light Microscope:
A
only uses light
4
Q
Electron Microscope:
A
beam of electrons is used to magnify
5
Q
What are the two types of electron microscopes?
A
the transmission electron microscope (TEM) and the scanning electron microscope (SEM)
6
Q
What are transmission electron microscopes (TEM) used for?
A
to visualize the internal structures of extremely small samples, like cells, viruses, or nanomaterials
7
Q
What are scanning electron microscopes (SEM) used for?
A
produces detailed, magnified images of an object. Micrographs show what the object is made of and its physical features. more 3D
8
Q
Which electron microscope has a higher magnification?
A
Transmission Electron Microscopes (TEMs)
9
Q
How much magnification can be attained with a light microscope?
A
40x to 1000x
10
Q
What is a prokaryote?
A
a microscopic single-celled organism that has neither a distinct nucleus with a membrane nor other specialized organelles (bacteria and cyanobacteria)
11
Q
What is a eukaryote?
A
any cell or organism that possesses a clearly defined nucleus (plants and animals)
12
Q
Prokaryote Structures
A
cell membrane, loose DNA, cytoplasm
13
Q
Eukaryote Structures
A
nucleus, mitochondria, membrane-bound organelles, cytoplasm and cytosol some times a cell wall (plants)
14
Q
Cytosol
A
fluid between all the organelles in eukaryotic cells
15
Q
Cytoplasm
A
everything inside the membrane except the nucleus
16
Q
What are the structures in a typical bacteria?
A
fimbriae, nucleoid, ribosomes, plasma membrane, cell wall, glycocalyx, flagella
17
Q
Fimbriae
A
attachment structures on the surface of some prokaryotes (little hairs)
18
Q
Nucleoid
A
region where the cell’s DNA is located - not enclosed by a membrane (prokaryote)
19
Q
Plasma Membrane
A
membrane enclosing the cytoplasm (every cell)
20
Q
Cell Wall
A
rigid structure outside of the plasma membrane (not animals)
21
Q
Glycocalyx
A
the outer coating of many prokaryotes - capsule or slime layer
22
Q
Flagella
A
locomotion organelles of some prokaryotes - tails
23
Q
What are the parts of the cells shared by both plants and animals?
A
the nucleus, with the nuclear envelope, nucleolus, and chromatin, endoplasmic reticulum, Ribosomes, cytoskeleton with microfilaments and microtubules, plasma membrane, peroxisome, mitochondria, Golgi apparatus
24
Q
What parts of the cell are unique to plants?
A
cell wall, plasmodesmata, chloroplast, central vacuole
25
What parts of the cell are unique to animals?
flagellum, microvilli, centrosome, lysosome
26
What are the parts of an animal cell?
flagellum, centrosome, cytoskeleton with microfilaments, intermediate filaments, microtubules, microvilli, peroxisome, mitochondria, lysosome, Golgi apparatus, ribosomes, plasma membrane, nucleus with nuclear envelope, nucleolus and chromatin, endoplasmic reticulum (rough and smooth)
27
What are the parts of a plant cell?
nucleus (nuclear envelope, nucleolus, chromatin), Golgi apparatus, mitochondria, peroxisome, plasma membrane, cell wall, plasmodesmata, chloroplast, cytoskeleton (microfilaments, microtubules) central vacuole, ribosomes, endoplasmic reticulum (smooth and rough)
28
Centrosome
contains a pair of centrioles - t shaped churro, which organizes and initiates the growth of microtubules (animal)
29
Cytoskeleton
reinforces the cell's shape, functions in cell movement, components made of protein has three parts - microfilaments, intermediate filaments, microtubules (eukaryotes)
30
Microtubules
the thickest components are hollow rods that shape cells, guide the movement of organelles, separating chromosomes during cell division - lines lining the cell membrane (eukaryotic)
31
Components of cytoskeleton thinnest to thickest
microfilaments, intermediate filaments, microtubules
32
Microfilaments
thinnest, solid rods built as twisted double chains, structural role is to bear tension, resisting pulling forces on the cell, and they form a 3-D cortex that is just inside the plasma membrane and helps to support the cell's shape - goes from membrane to organelles
33
Intermediate Filaments
middle size supports cell shape, and fixes organelles in space, a more permanent cytoskeleton picture than the other two - go longitudinal between the other two
34
Microvilli
membrane projections that increase the cell's surface area - basically bumps or skin tags (animal)
35
Peroxisome
bunch or metabolic functions produces hydrogen peroxide as a by-product and then converts it to water - a small ball with a structure in the middle of it (eukaryotic)
36
Mitochondria
where cellular respiration happens and most ATP is generated - bean with a maze in it (eukaryotic)
37
Lysosome
digestive organelle where macromolecules are hydrolyzed (breaking down and adding water) - small ball (eukaryotic)
38
Golgi Apparatus
processing and packaging center, modifying proteins, sedning them elsehwere - a bunch of canyons with no balls attached (eukaryotic)
39
Ribosomes
make proteins that are free in the cytosol or bound to rough ER or nuclear envelope, made of rRNA and protein - lil tiny balls (all cells)
40
Nucleus
were all DNA is stored and has three parts (nuclear envelope, nucleolus, chromatin)- big ball (eukaryotic)
41
Nuclear Envelope
double membrane enclosing the nucleus, perforated by pores and connected to rough ER (eukaryotic)
42
Nucleolus
non-membraneous structure involved in the production of ribosomes - between center and outside of nucleus (eukaryotic)
43
Chromatin
material with DNA and proteins - middle of the nucleus (eukaryotic)
44
Endoplasmic Reticulum ER
network or membraneous sacs and tubes that create membranes and do other things with metabolism has rough and smooth (eukaryotic)
45
Rough ER Look
maze surrounding the nucleus with ribosomes on it
46
Smooth ER Look
coral-looking thing connected to the rough one
47
Cell Wall
the outer layer that maintains the cell's shape and protects it from damage, made of cellulose, other sugars, and proteins (plants)
48
Plasmodesmata
cytoplasmic channels through cell walls that connect the cytoplasm of adjacent walls (plants) - lil dots on cell wall
49
Chloroplast
where photosynthesis happens (sunlight to chemical E in sugar molecules)- green ovals with springs inside (plants)
50
Central Vacuole
mostly in older cells, does storage, breaks down waste products, hydrolysis of macromolecules (water used to break down a compound), bigger vacuoles= plant growth - big empty bean filled with water (plants)
51
Structure of Cell Membrane
hydrophilic tails face each other and hydrophobic heads face out which keeps water out - phospholipid bilayer
52
Transmembrane Proteins
allows passage of hydrophilic substances across the membrane, mostly moving down the gradient but active transport can move them against the concentration gradient which allows cells to maintain concentration gradients that different than their surroundings
53
Aquaporins
channel proteins that greatly facilitate the passage of water can be gated ( respond to a stimulus)
54
Why is facilitated diffusion passive?
because the solute moves down the concentration gradient
55
Sodium-Pottasium Pump
transport protein that is energized by the transfer of a phosphate group (Po4) from hydrolysis (breakdown with water) of ATP
56
What kind of amino acids are found on the transfer proteins embedded in the cell membrane?
Hydrophobic, because cytoplasm and extracellular fluid are very aqueous
57
What kind of amino acids are found on the transfer proteins inside and outside the cell?
polar or charged amino acids (hydrophilic) because the fluid is very aqueous
58
What are the components of the endomembrane system?
nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, plasma membrane - they are continuous or connected by vesicles
59
Central Dogma of Biology
DNA - RNA - Protein
60
DNA to RNA
transcription
61
RNA to Protein
translation
62
What organelles are involved in energy transfer?
mitochondria (cellular respiration) and chloroplasts (photosynthesis)
63
Flow of Biological Energy
sun - sugar - ATP - cellular work
64
sun to sugar
photosynthesis
65
sugar to ATP
cellular respiration
66
ATP to cellular work
ATP becomes hydrolyzed into ADP, or further to AMP, and free inorganic phosphate groups
67
What is the endosymbiont theory?
mitochondria and plastids were once free-living prokaryotic cells that were engulfed by eukaryotic cells, becoming organelles within them
68
Centriole
a cylindrical organelle that comes in pairs inside a centrosome that each has 9 triplets of microtubules arranged in a ring
69
How do cilia and flagella move?
dynein arms alternate;y grab, move and release the outer microtubules and that force cause doublets to curve which bends the cilium or flagella and protein cross-links limit sliding
70
Dynein
a family of molecular motors that use chemical energy from ATP to move along microtubules in cells
71
What is the arrangement of microtubules in flagella and cilia?
9+2 array- nine pairs of microtubule doublets in cylindrical shape around a central pair of microtubules
72
What is a basal body?
a small, protein-based structure found at the base of a cilium or flagellum, acting as a platform for the construction of these structures
73
Structure of Basal Bodies
9(3)+0 - nine sets of triplet microtubules that look like they are connected like spokes on a wheel (cartwheel structure)
74
Glycosylation/glycosylated
a process in which a carbohydrate is attached to a protein or lipid, forming a glycoconjugate - carbohydrates that are covalently linked to other biological molecules, such as proteins, lipids, peptides, and amino acids.
75
How do actin and myosin interact during muscle contraction?
The myosin reaches forward, binds to actin, contracts, releases actin, and then reaches forward again to bind actin in a new cycle
76
cell wall functions
provide structural support, maintain cell shape, protect the cell from mechanical stress, regulate osmotic pressure, and facilitate cell-to-cell communication
77
What kinds of cells have walls?
fungi, algae, plants and mollicute bacteria
78
What kinds of molecules make up the extracellular matrix in animals?
fibrous proteins, glycosaminoglycans (GAGs), and glycoproteins
79
Where do the molecules in the extracellular matrix come from?
made in connective tissues like fibroblasts
80
Glycoproteins
a protein with sugar molecules attached to it that aid in immunity, cellular interactions, and molecular recognition.
81
Proteoglycans
proteins with a core and one or more glycosaminoglycan (GAG) chains attached to it - sugar chains
82
Fibronectin
a glycoprotein that acts as a link between cells and extracellular matrices in animal and human tissues and is involved in cell-adhesive interactions, wound healing and tissue engineering
83
Functions of the Extracellular Matrix
provide structural support for cells and tissues, while also actively regulating cell behavior by influencing cell adhesion, migration, proliferation, differentiation, and overall tissue development
COMMUNICATION
84
plasmodesmata
cytoplasmic channels that connect plant cells and allow the movement of molecules between them, located in the cell wall
85
Tight Junctions
protein complexes that create a watertight seal between animal cells that prevent water and ions from flowing between cells, creating a semipermeable barrier that controls paracellular permeability
(epithelial tissue)
86
Desmosomes
cell junctions that act like spot welds between animal cells, holding them together in tissues and organs that stretch, creating a sheet-like formation (skin, lining of the mouth)
87
Gap Junctions
specialized protein channels that directly connect the cytoplasm of two adjacent cells, To facilitate the direct transfer of small molecules between neighboring cells, enabling coordinated cellular activity within a tissue (cardiac and smooth muscle)
88
What does a semi-permeable or selectively permeable membrane mean?
allows certain molecules to pass through while blocking others
89
amphipathic molecules
chemical compounds with both polar and nonpolar regions. They have both hydrophilic (water-loving) and lipophilic (fat-loving) properties.
90
What is meant by the fluid mosaic model of membranes?
the membrane is not static but behaves like a fluid with diverse components embedded in it, constantly moving around
91
Integral Membrane Proteins
proteins that are permanently attached to a biological membrane and are essential for life - in lipid bilayer
92
Peripheral Membrane Proteins
proteins that temporarily attach to the surface of a cell membrane or are partially embedded in it - surface of lipid bilayer
93
Diffusion
substances naturally spread out from a concentrated area to a less concentrated area, without requiring energy input (down a concentration gradient)
94
What is meant by movement “against a concentration gradient?
from an area of lower concentration to an area of higher concentration
95
What is the difference between active and passive transport?
active transport requires cellular energy to move substances across a cell membrane against their concentration gradient, while passive transport does not require energy and substances move naturally down the concentration gradient
96
What is osmosis?
water molecules move through a semipermeable membrane from an area of high concentration to an area of low concentration
97
Tonicity
the ability of a solution to change the volume of a cell by altering its water content
98
Isotonic
The volume of cells suspended in the solution does not change
99
hypertonic
Water moves out of the cell
100
Hypotonic
Water moves into the cell
101
What is osmoregulation?
The process by which organisms maintain the balance of water and salt in their bodies - homeostasis
102
Aquaporins
membrane proteins that facilitate water transport, solute transport, cell migration, and tissue swelling, they use osmosis
103
Facillitated Diffusion
Facilitated diffusion allows polar and charged molecules to cross the plasma membrane and from high to low concentration where transport molecules do not dissolve in the membrane
104
What are ion channels
proteins that form pores in cell membranes, allowing ions to pass through and down their electrochemical gradient
Ex) muscle contraction, insulin release
105
What is the energy source for active transport?
ATP
106
What does phosphorylation mean and what does it cause?
the addition of a phosphoryl (PO3) group to a molecule alters the structural conformation of a protein, causing it to become activated, deactivated, or otherwise modifying its function
107
Sodium-potassium pump
moves sodium ions out of the cell and potassium ions into the cell with active transport. This process helps maintain the cell's resting membrane potential, cell volume, and osmotic equilibrium, which is important because of its role in many essential bodily functions
108
membrane potential
The gradient of electrical potential energy across a cell membrane - the difference between inside and outside the cell
109
What is an electrochemical gradient?
the difference in charge and chemical concentration across a membrane
110
what does electrochemical gradient do in active transport?
acts as the driving force that pushes ions or molecules across a cell membrane against their concentration gradient by either using ATP (primary) or stored energy (secondary)
111
What is an electrogenic pump?
a transport protein that moves ions across a cell membrane, creating a voltage difference across the membrane. The pump moves three sodium ions out of the cell, and for every two potassium ions, it moves in. This process creates a net outward current, making the inside of the cell negative.
112
major electrogenic pump in animal cells
sodium-potassium pump
113
major electrogenic pump in plant cells
proton pump
114
Cotransporter
membrane proteins that move two different molecules or ions across a cell membrane by coupling the movement of an ion down its concentration gradient with the movement of a cotransported molecule against its concentration gradient, found in small intestine, kidney, brain, placenta, and blood cells
115
how large molecules and particles are transported across membranes
bulk transport which involves the formation of vesicles, small membrane-bound sacs, that engulf the large molecules and move them across the membrane by fusing with the cell membrane; this process is further divided into endocytosis (bringing molecules into the cell) and exocytosis (releasing molecules from the cell)
116
Types of endocytosis
phagocytosis, pinocytosis, and receptor mediated endocytosis
117
Phagocytosis
Also known as "cell eating", phagocytosis is when a cell engulfs large particles or other cells, such as bacteria or damaged cells
118
Pinocytosis
Also known as "cell drinking", pinocytosis is when a cell takes in dissolved nutrients and fluids in small vesicles.
119
receptor-mediated endocytosis
specific substances bind to receptor proteins on the outside of the cell and are then engulfed into the cell in clathrin coated vesicles
120
How does exocytosis work?
a vesicle (a small, membrane-bound compartment) containing the molecules to be released fuses with the cell membrane, and the contents of the vesicle are expelled
