Cell Biology Unit 2 Flashcards
1
Q
What are the fundamental units and the smallest units of life?
A
Cells
2
Q
What do ALL cells have?
A
Plasma Membrane, DNA, Ribosomes, Cytosol/Cytoplasm
3
Q
What cells can life be divided into?
A
Prokaryotes and Eukaryotes
4
Q
What are the 3 parts of Cell Theory?
A
- Cells are the basic unit of structure and function
- All living organisms are made of cells
- All cells come from PRE-existing cells
5
Q
What are the domains classified as Prokaryotes?
A
Bacteria and Archaea
6
Q
What kingdoms hold Eukaryotes?
A
Protists, Fungi, Plants, and Animals
7
Q
What do you have to have to be considered a prokaryote?
A
No Nucleus, Less organelles, single celled, either a bacteria or archaea, non-membrane bound organelles
8
Q
What do you have to have to be considered a eukaryote?
A
Nucleus, membrane-bound organelles, either a fungi, protist, plant, or animal, and multi-cellular
9
Q
What happens when cells are too large?
A
They will starve to death or drown in their own waste; the process to take in nutrients or excrete waste through their plasma membrane is slowed down
10
Q
Why are small cells the best cells?
A
When taking in nutrients and excreting waste, the process is very fast; nutrients come in sooner and wastes exits body faster
11
Q
Describe a nucleus
A
Usually the largest organelle in the cell; contains DNA, RNA, and proteins
12
Q
What is a nuclear envelope?
A
Protects the DNA from DNAse enzymes in the cytosol that destroys DNA
Located on the outside of the nucleus for protection
13
Q
What is a pore complex?
A
Located on the nuclear envelope
Allows and control what molecules enter and exit the nucleus
14
Q
What is a chromatin?
A
Is a complex of DNA and proteins; make up eukaryotic chromosomes
15
Q
What is a nucleolus?
A
1 or more regions in nucleus; does not have a membrane around it
Function: Involved in processing RNA and making ribosomes
16
Q
What are ribosomes and their functions?
A
In both prokaryotes and eukaryotes; it is put together in the nucleolus
Complex of rRNA and protein molecules, it is the site of protein synthesis
17
Q
What is in the Endomembrane System? What is the Endomembrane System?
A
- An extensive series of membranes
Endoplasmic Reticulum (RER, SER)
Lysosomes
Vacuoles
Golgi Apparatus
18
Q
What is an endoplasmic reticulum?
A
Complex membranes associate with nuclear envelope divided into 2 sections
1. Smooth Endoplasmic Reticulum (SER)
2. Rough Endoplasmic Reticulum (RER)
19
Q
What is the function of the SER?
A
Makes cellular products like hormones and lipids
20
Q
What is the function of RER?
A
Produces proteins for the cell; site for protein synthesis
21
Q
What is the Golgi Apparatus and its functions?
A
Made of flattened membranes
Responsible for shipping and receiving center for proteins
22
Q
What are lysosomes and its functions?
A
Digestive compartments in ANIMAL cells
a. Phagocytosis- cell eating
b. Organelle recycling or autophagy
23
Q
What is a vacuole and its functions?
A
Considered specialized lysosomes
Central vacuoles found in plant cells (vacuoles can be found in both animals and plant cells)
Maintenance compartments that function as food vacuoles and contractile vacuoles
- Store large amounts of water, helps maintains its firm shape
24
Q
What is the mitochondria and its function?
A
Considered the “powerhouse” of the cell
Produces ATP
Comprised of an outer, inner membrane and the matrix
Mitochondrial DNA to trace matrilineal line
25
What is the Endosymbiotic Theory?
Origin of the mitochondria and chloroplasts
26
What are centrosomes and its functions?
Structure in the cytoplasm of an animal cell; microtubule organizing structure with two centrioles
Functions in cell division
27
What are cytoskeletons and its functions?
Network of microtubules, microfilaments, and intermediate filaments that extend throughout the cytoplasm
Serve a variety of mechanical, transport, and signaling functions
28
What are in cytoskeletons?
Microtubules
Microfilaments
Intermediate Filaments
29
What do microtubules do in the cytoskeleton?
Hollow tubes (compression-bearing elements)
1. maintenance of cell shape
2. cell motility
3. organelle movements
30
What do microfilaments do in the cytoskeleton?
Two intertwined strands of actin (tension-bearing elements)
1. maintenance of cell shape
2. changes in cell shape
3. muscle contractions
31
What do intermediate filaments do in the cytoskeleton?
Fibrous proteins coiled into cables (tension-bearing elements)
1. Maintenance of cell
2. Anchorage of nucleus and certain other organelles
3. Formation of nuclear lamina
32
Describe the Cilium and its functions
Short appendages containing microtubules in eukaryotic cells
Motile Cilium- specialized for locomotion and movement of fluid past the cell
Primary Cilium- usually nonmotile; plays a sensory and signaling role
33
Describe the flagellum and its function
Long cellular appendage
Specialized for locomotion
34
What organelles are unique to plant cells?
Cell Wall
Chloroplast
Vacuoles
35
Describe chloroplasts and its function
Only found in plants and photosynthetic protists
Synthesizes complex carbohydrates from sunlight and CO2 through the process of photosynthesis
36
Describe cell wall and its functions
Surrounds the plasma membrane of plants cells
Provides strength and protection for the internal contents of the cell
Regulates cell growth
37
What are ALL cells surrounded by?
Plasma Membrane
38
What are the functions of the plasma membrane?
Regulates what goes into or comes out of the cell (Bouncer of the cell); NOT FILTERS
Separates outside from inside of the cell
Goes in: Food such as glucose, water, and oxygen
Goes out: Waste such as CO2 among other cells
39
What are the characteristics of the plasma membrane?
Semi-permeable/selectively-permeable
Strong
Flexible
40
What is the Fluid Mosaic Model of the Plasma Membrane?
All membranes are a combination of phospholipids arranged in the bilayer
- Proteins are embedded in this phospholipid bilayer
Received the name because the membrane with its different components look like a mosaic
41
What are the (4) main components of the Plasma Membrane?
1. Phospholipid Bilayer
2. Protein
3. Cholesterol
4. Carbohydrates
42
What is the function of the phospholipid bilayer in the plasma membrane?
Forms a bilayer to make the membrane
Can only move LATERALLY
Only allows small uncharged molecules (O2, CO2, N2, steroids) and small uncharged polar molecules (H2O, glycerol, urea, and ethanol) passes through
43
What is the function proteins in the plasma membrane?
Transport
Enzymes
Receptors
Cell ID
Joining Cells
44
What is the function of cholesterol for plasma membranes?
Add rigidity to animal membranes
45
What is the function of carbohydrates of a plasma membrane?
Located on the outside of the cell, which are used by the immune system of mammals to recognize whether a cell is friend or foe
46
What can pass through the plasma membrane?
Small uncharged polar molecules
H2O, CO2, Urea, N2, O2, Steroid, Ethanol Glycerol
47
What cannot go through the plasma membrane?
Large uncharged polar molecules
Glucose, sucrose, Na+, Cl-, Ca2+, H+, K+
48
What are the two types of carbohydrates and what are they attached to?
1. Glycoproteins: attached to proteins
2. Glycolipids: attached to the lipid head
49
What are the two types of protein, their functions and where are they located?
1. Integral Proteins: Between the phospholipid bilayer; often transport and sometimes as enzymes
2. Peripheral Proteins: Under bilayer; involved in cell signaling
50
What are intercellular joining and the (3) types?
How cells are joined together
1. Gap Junctions
2. Desmosomes
3. Tight Junctions
51
What are Gap Junctions?
Cytoplasmic channels between cells in plants and heart muscles
52
What are Desmosomes?
Acts as rivets to glue cells together as muscles cells
53
What are Tight Junctions?
Seal cells together as in epithelial cells
54
What are the two things proteins can be attached to?
Extracellular matrix and microfilaments of the cytoskeleton
55
What are the (4) types of transport for proteins?
1. Diffusion
2. Equilibrium
3. Osmosis
4. Active Transport
56
What are the different types of diffusion?
Passive Diffusion
Facilitated Diffusion
57
Describe passive diffusion
Requires no energy to move from high to low concentration
58
Describe facilitated diffusion and the types of proteins used
Can also be passive, however uses a protein to aid in passing through molecules
Passive transport aided by proteins
Channel Proteins
Carrier Proteins
59
What are channel proteins?
A type of transport protein; uses tunnels through the membrane
Size of channel determines what molecules passes through
60
What are carrier proteins?
Shape-changers to bring molecules through the membrane with protein
Rocking motion used to get molecules through
61
What is osmosis?
Movement of free water; passage of water molecules across semi-permeable membrane from a solution with high concentration to a solution with a lower concentration
62
What are Aquaporins used in osmosis?
Channel proteins used to passively transport water across the membrane with no energy
63
What is used to study osmosis in lab?
Dialysis Tubing
64
What are cells and extracellular fluids considered?
Solutions
65
Describe the active transport and what is required to perform
Cells need to transport molecules AGAINST the concentration gradient
Requires:
1. Energy, usually ATP
2. Carrier protein
66
What are the (3) basic types of active transport pumps?
1. Uniport
2. Symport
3. Antiport
67
What is the primary active transport pump and most important?
Na+/K+ Pump
An antiport; transport 3 Na+ from inside to outside and 2 K+ from outside to inside
68
What is cotransport or secondary transport?
Transport of 2 solutes with different concentration
When one solute moves down the concentration gradient, it creates energy for another solute to move down the gradient as well
69
What is a coupled transport?
Have 2 carrier proteins involved 1st carrier protein uses ATP to move substance 1 across the membrane against gradient (storing potential energy); then it allows substance 2 to move up its concentration gradient
70
What is vesicular/bulk transport?
Moves molecules across the membrane that are too BIG for channels or carriers
71
What are the 2 mechanisms of bulk transport?
1. Endocytosis- movement of materials in cell via membranous vesicles
2. Exocytosis- movement out of cells via membranous vesicles
72
What is phagocytosis and pinocytosis in endocytosis?
Phagocytosis is the intake of solid particle
Pinocytosis is the intake of liquids
73
What is local signaling?
Animal cells involve direct contact or the secretion of local regulators
74
What is long distance signaling?
Animal and plant cells uses HORMONES
Animals can also pass signals electrically
75
Just like epinephrine, what are the three stage cell signaling pathways that hormones bind to membrane receptors?
1. Reception
2. Transduction
3. Response
76
What is reception in the signal transduction pathway?
A signaling molecules binds to a receptor protein, causing it to change shape
77
What are the (3) major types of cell-surface transmembrane receptors?
1. GPCRs
2. RTKs
3. Ligand-gated Ion Channels
78
What is a signaling molecule called?
Ligand
79
What are intracellular receptors?
Is a type of reception that occurs in the cell because the signaling molecule is either hydrophobic or small enough to cross the plasma membrane
- Are cytoplasmic or nuclear proteins
80
What is apoptosis?
Integrates multiple cell signaling pathways
A type of programmed cell death in which cell components are disposed of in an orderly fashion
81
What are the two main enzymes involved in apoptosis which death signals leads to activate?
1. Caspases
2. Nucleases
82
What is metabolism?
Interaction between molecules, may build large molecules from smaller ones and some breaking down large molecules into smaller ones
- Manages the material and energy resources of the cell
83
What are metabolic pathways? What are the two types of pathways?
Series of defined steps beginning with a starting molecule and ending with a PRODUCT
Catabolic Pathways
Anabolic or biosynthetic pathways
84
What are catabolic pathways?
Breaks down larger molecules to smaller ones; releasing energy
- Cellular Respiration
85
What are anabolic or biosynthetic pathways?
Build up large biomolecules from smaller ones
- Usually REQUIRES energy
86
What is the 1st Law of Thermodynamics?
Energy can be transferred and transformed but it CANNOT be created or destroyed
- Not 100% efficient; energy is lost most times (heat) which INCREASES entropy/disorder in the world
87
What is the 2nd Law of Thermodynamics?
Every energy transfer or transformation INCREASES the entropy of the universe
88
What is entropy?
Measure of molecular disorder or randomness
89
What is Free Energy (delta G)?
Energy that is needed at a given temperature and entropy
90
What happens when G<0?
The reaction is spontaneous
91
What happens when G>0?
Reaction needs input energy and is unstable
92
What is the formula for free energy (delta G)?
energy of the final state- energy of the initial state
93
What does ATP power?
Cellular Work
94
What are the (3) main kinds of work that uses ATP?
1. Chemical work: Often making larger molecules from smaller ones where the product(s) have higher free energy so less entropy in products
2. Transport work: Active transport against concentration gradient
3. Mechanical work: such as moving cilia or moving muscles
95
What is ATP and the structure?
Type of nucleotide
Made of adenine, ribose sugar, 3 phosphates
96
What is the structure of ADP?
Made of adenine, ribose sugar, and 2 phosphates
97
What does hydrolysis do to ATP?
When adding water to break down ATP it turns into ADP+ Pi + Energy
98
What does 2 molecules need for a chemical reaction to occur?
Sufficient force and correct orientation
99
What is exergonic (exothermic) profile?
Energy is leaving the reaction
100
What is endergonic (endothermic) profile?
Takes energy out of the environment
101
What are enzymes?
Proteins that increase the success of chemical reaction by lowering energy of activation
- Makes chemical reactions happen faster
102
How do enzymes work?
Active sites are formed in the protein enzyme, substrates (reactants) are then placed in that site so a reaction can occur
If the reaction is endergonic, ATP may be used
If the reaction is exergonic, ATP may be made from ADP
103
Are enzymes substrate specific?
Yes, they only allow substrates attach to them
104
What are factors that affect enzymes activity?
Temperature, pH, Substrate Concentration
105
What are enzyme inhibitors?
Inhibitors slow down or completely stop an enzymatic reaction
106
What are the three types of enzyme inhibitors?
Competitive
Non-competitive
Allosteric Activators
107
What is a feedback inhibitor?
A form of non-competitive inhibitor that involves in regulating pathways
108
What does it mean for an enzyme to be a catalyst?
Not used up in the reaction
109
