Unit 2 Flashcards
1
Q
Define a cell.
A
The fundamental unit of life.
2
Q
What two ways do we study cells?
A
Microscopy
AND
Cell fractionation
3
Q
What three things does the quality of a microscopy image depend on? Define each on.
A
- Magnification-ratio of an object to its size
- Resolution-measure of clarity; minimum distance of 2 distinguishable points
- Contrast- visible differences in parts of a sample
4
Q
Describe the functions of a light microscope.
A
- Light passes through specimin>passes through lens system to magnify image
- Magnifies approx. 1000x
- Has various techniques to enhance contrast
- Can’t resolve most sub cellular structures
5
Q
What are the two types of electron microscopes and describe how they work.
A
- Scanning electron microscope- focus beam of e- onto the surface of a specimen > 3D image> specimen must be coated in a film of gold
- Transmission Electron Microscope- focus beam of e- through a specimen> 2D image>specimen covered w/ heavy metal
6
Q
Define cell fractionation.
A
the act of taking apart and separating cells (separating major organelles)
7
Q
What four features are common in all cells?
A
They all have:
- Plasma membrane
- Cytosol
- Chromosomes
- Ribosomes
8
Q
Describe a prokaryotic cell.
A
Has no nucleus, (the DNA is located in the nucleoid), no membrane bound organelles, and cytoplasm bound by the plasma membrane
9
Q
Describe a eukaryotic cell.
A
The DNA is in a nucleus bound by a membrane envelope, membrane bound organelles, cytoplasm is the region between plasma membrane & nucleus
10
Q
What are the two groups of organelles?
A
Endomembrane system and Energy conversion
11
Q
Define the endomembrane system.
A
A system that consists of membranes that are directly/indirectly connected by transport vesicles.
12
Q
What organelles are apart of the endomembrane system and what are their functions?
A
- Nucleus- information center
- Endoplasmic reticulum- factory
- Golgi apparatus- shipping and receiving
- Lysosomes- digestive compartments- dissassembly components
- Vacuoles- maintenance & storage compartments
13
Q
What organelles take part in energy conversion and what are their functions?
A
- Mitochondria- energy production (have their own DNA)
- Chloroplast- make sugars small carbohydrates
- Peroxisome- breakdown compartment
14
Q
Describe the nuclear envelope.
A
A double membrane (two lipid bilayers) that encloses the nucleus
15
Q
What is the function of the nuclear pores on a nucleus?
A
To regulate entry and exit from nucleus
16
Q
What is the nuclear lamina?
A
A protein filament that maintains the shape of the nucleus
17
Q
Define chromatin.
A
The genetic material formed by the nucleus DNA & associated proteins. Which condenses to form chromosomes.
18
Q
Define the nucleolus and its location.
A
The site of ribosomal RNA (rRNA) synthesis, located within the nucleus.
19
Q
Describe the function of ribosomes and the two locations they are located.
A
They cary out protein synthesis in two locations in the
- Cytosol- proteins for use in the cytosol on the
- ER- proteins for use elsewhere
20
Q
Describe the smooth er and its function.
A
- Lacks ribosomes
- Synthesizes lipids
- Metabolizes carbs
- Detoxifies poisons
- Stores calcium
21
Q
Describe the rough er and its function.
A
Ribosomes on the surface secrete glycoproteins and distributes transport vesicles membrane factory for cell
22
Q
The golgi apparatus consists of flattened membranous sacs called ____
A
cisternae
23
Q
What are the functors of the golgi apparatus?
A
Modify products of ER
Manufacture some macromolecules sort and package materials into transport vesicles
24
Q
Membranous sacs of hydrolytic enzymes that digest all four classes of biological macromolecules: ?
A
lysosome
25
Describe phagocytosis.
when a cell engulfs another cell
26
Describe autophagy.
Site of recycling organelles in a cell
27
Describe vacuoles and their function
* The container for cells
* Food vacuoles are found by phagocytosis
* Contractile vacuoles found in many freshwater protists
* Central vacuoles are found in mature plants; hold water and organic molecules
28
Which two organelles have a double membrane and their own DNA.
Mitochondria and Chloroplasts
29
Describe a mitochondria.
Has a smooth outer membrane
Highly folded inner membrane- folded into cristae inner membrane separates inter membrane space and mitochondrial matrix
30
Describe chloroplasts.
member of the family plastids contain green pigment chlorophyl and molecules that function in photosynthesis CO2 ---\> small carb Found in leaves and other green organs of plants
31
What is the structure of a *chloroplast*?
It contains *thylakoids*- stacks of membranous sacs called GRANUM as well as *storma*- internal fluid
32
What are peroxisomes?
Specialized metabolic compartments bound by single membrane. Use oxygen to break down molecules
33
Define cytoskeleton.
A network of fibers extending throughout the cytoplasm it organizes the cell's structures and activities
34
Describe *microtubules* and state their functions.
* thickest hollow rods
* approx. 25nm
* grow out of centrosome near the nucleus
Function: shaping the cell, move organelles, separating chromosomes
35
Describe *microfilaments* and state their functions.
* A.k.a Actin Filaments
* thinnest components
* solid rods
* approx 7nm
Function: cell shape, microvilli of intestinal cells
36
Describe *intermediate filaments* and state their functions.
* middle sized
* range from 8-12 nm
* most permanent fixtures of cytoskeleton
function: cell shape, fix organelles in place
37
What are two things microtubules make?
Cilia and flagella
38
What are two types of microfilaments and what are their function?
Actin and Myosin cellular motility muscle contraction ameboid movement cytoplasmic streaming
39
What are the three extracellular components?
Cell walls of plants, extracellular matrix, intercellular junctions
40
Describe the cell wall of a plant and its structure.
protect the cell from excessive uptake of water made up of cellulose
Structure: -_primary cell wall_: thin and flexible
- _middle lamella_: thin layer between 1 degree cell walls
- _secondary cell wall_: (some cells) between plasma membrane
41
Define extracellular matrix.
Made up of glycoproteins such as collagen, proteoglycans, and fibronectin cover animal cells
42
What are integrins?
Receptor proteins in the plasma membrane that ECM proteins bind to and go through the membrane
43
What are the functions of the extracellular matrix?
support, adhesion, movement, and regulation
44
What is the function of intercellular junctions?
To facilitate the physical contact of neighboring cells when they adhere, interact, and communicate
45
What are the different types of intercellular junctions?
Plasmodesmata, Tight Junctions, Desomosomes, and Gap Junctions
46
Define plasmodesmata.
channels that perfovak cell walls, allows water and small solutes to pass
47
Define tight junctions.
membranes of neighboring cells pressed together to prevent leakage of extracellular fluids
48
Define desmosomes.
anchoring junctions- fasten together cells in strong sheets
49
Define gap junctions.
provide cytoplasmic channels between adjacent cells
50
Boundary that seperates cell from surroundings\_\_\_\_.
**Plasma membrane**
51
Molecules that contain hydrophobic and hydrophiic regions
Amphibic
52
Describe the role of cholesterol.
* At warm temps- cholesterol restrains movement
* At cool temps- cholesterol maintains fluidity of membrane
53
Describe peripheral proteins.
Bound to the surface
54
Describe integral proteins.
Pass through hydrophobic core
Aka Transmembrane protiens
55
List the functions of membrane protiens.
* Transport
* Enzymatic activity
* Signal transduction
* cell to cell recognition
* intercellular joining
* attachment to ECM
56
Describe passive transport. And list examples.
No energy investment
Ex: Diffusion & Osmosis
Faciliated Diffusion- channel proteins and carrier proteins
57
Describe active transport. And list examples.
Energy investment, moves molecules and solutes agaisnt concentration gradient.
Ex: Ion pumps, CoTransport
Bulk transport- endocytosis, exocytosis
Phagocytosis-cellular eating
Pinocytosis- cellular drinking
Receptor- mediated endocytosis
58
What qualities do molecules that pass easily through the membrane have?
* Hydrophobic
* Nonpolar
* Hydrocarbons
59
Define transport proteins.
Protiens that provide a hydrophilic channel through which polar molecules can pass.
60
Tendency for molecules to spread out evenly in space.
*Diffusion*
61
Diffusion of water across selectively permeable membrane
*Osmosis*
62
Abilty of a solution to cause a cell to gain/lose water.
*Tonicity*
63
When solute concentrates are the same inside & outside the cell it said to be \_\_\_\_\_.
*Isotonic*
64
When solute concentration\> than insdie the cell and the cell loses water, it is said to be \_\_\_\_.
*Hypertonic*
65
When solute concentration\< than inside the cell and the cell gain water it is said to be \_\_\_\_.
*Hypotonic*
66
Transport proteins speed the passive movement of molecules across the plasma memebrane. This process is called \_\_\_\_.
Facilitated Transport
67
What is the function of channel proteins?
They provide corridors that allow specific molecules or ions to cross the cell membrane.
68
What are the three channel proteins and their function?
* Aquaporins- facilitate diffusion of H2O
* Ion Channels- Open/Close in response to stimulus
* Carrier Proteins- undergo a subtle change in structure and translocate solute
69
Define active transport.
Use of energy to move solutes _against_ concentration gradient
70
When active transport of solute indirectly drives transport of another solute is called \_\_\_\_.
Cotransport
71
When transport vesciles migrate to membrane, fuse w/ it then release contents.
Exocytosis
72
What does endocytosis consist of ?
* Phagocytosis- cellular eating (solids)
* Pinocytosis- cellular drinking (liquids)
* Receptor-mediated endocytosis
73
Describe metabolism.
Tranforming matter & energy
74
Catabolic reactions \_\_\_?
Release energy by breaking down complex molecules into simplier molecules.
75
Anabolic reactions\_\_\_\_\_?
Consume energy to build complex molecules from simplier ones.
76
The study of how organisms manage energy reuses
Bioenergetics
77
Define energy.
The capacity to do work and cause change.
78
Define kinetic energy and heat.
Energy associated w/ motion
* heat- thermal energy is kinetic energy associated w/ the motion of atoms or molecules.
79
How many NADH, ATP, and FADH2 are made in **ONE** turn of the Citric Acid Cycle?
* NADH = 3
* ATP = 1
* FADH2 = 1
80
How many turns of the Citric Acid Cycle does one glucose make?
Two turns, one turn for each pyruvate a glucose has (glucose = 2 pyruvate)
81
How many NADH, ATP, and FADH2 are produced from **ONE GLUCOSE** molecule?
* NADH = 6
* ATP = 2
* FADH2 = 2
82
Describe an exergonic reaction.
* A spontaneous reaction
* free energy decrease
* change in free energy (delta G) stability increases
* any energy given off can do work
83
Describe an endergonic reaction.
* a nonspontaneous reaction
* free energy (delta G) increases
* stability decreases
* work/energy is required
84
How does ATP work?
ATP becomes less stable by losing a phosphate becoming ATD, which makes it able to do work.
Adding an ATP to an endergonic (nonspontaneous) rection makes it exergonic (spontaneous)
85
The use of an exergonic (spontaneous) reaction to drive an endergonic (nonspontaneous) reaction is called \_\_\_\_.
Energy Coupling
86
Define entropy.
Disorder of energy.
87
OIL stands for?
Oxidation is loss of electrons.
88
RIG
Reduction is gain of electrons.
89
What is the main oxidizing agent of cellulalar respiration in which glucose is oxidized?
Oxygen
90
What are the three parts of cellular respiration?
1. Glycolysis
2. Citric Acid Cycle
3. Electron Transport Chain
91
The set of metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into ATP, and the release waste products is called \_\_\_\_.
Cellular respiration
92
Dehydrogenase
removes phosphates
93
Kinase (hexokinase)
adds phosphate
94
isomerase
creates an isomere
95
Synthetase
synthesizes a new molecule
