Exam 2 Flashcards
(162 cards)
1
Q
What are proteins?
A
macromolecules that perform majority of cell’s function
2
Q
What are amino acids?
A
monomers of proteins
3
Q
How many amino acid groups are there?
A
20 different side groups and 20 different amino acids
4
Q
What types of side groups are there for amino acids
A
Nonpolar (hydrophobic, no oxygen) polar (hydrophilic) charged (hydrophilic)
5
Q
What forms dipeptides
A
2 amino acids linked together
6
Q
What is a peptide bond?
A
Bond holding amino acids together within dipeptide
7
Q
What is a polypeptide
A
long polymer chains formed by linking hundreds of amino acid monomers
8
Q
What are the 4 levels of protein structure?
A
Primary, secondary, tertiary, quaternary
9
Q
What is primary structure?
A
polypeptides’ linear sequence of amino acids
10
Q
What is secondary structure?
A
local patterns formed in polypeptide chains
11
Q
What is tertiary structure?
A
entire polypeptide chain folded into its functional conformation
12
Q
What is the tertiary structure reinforced by
A
Hydrogen bonds, ionic bonds, disulfide bridges, van der Waals interactions.
13
Q
What are fibrous proteins?
A
Structural proteins
14
Q
What are globular proteins?
A
enzymes and other proteins
15
Q
What is quaternary structure?
A
when proteins consists of 2 or more polypeptide chains
16
Q
What can alter tertiary structure?
A
extreme of temp, pH, salinity or other environmental factors will lead to protein denaturing.
17
Q
What determines primary structure?
A
Nucleic acids
18
Q
What are nucleic acids?
A
inherited information that functions as a cell’s genetic material
19
Q
Examples of nucleic acids?
A
DNA, RNA
20
Q
What do nucleic acids do?
A
Store instructions for protein synthesis
21
Q
What does DNA do?
A
serve as temple for synthesizing RNA- transcription
22
Q
What does RNA do?
A
Serve as template for synthesizing proteins- translation
23
Q
A
24
Q
What are nucleotides held together with?
A
Nucleic acids by phosphodiester linkages
25
RNA nucleotides 3 components?
Sugar (deoxyribose) phosphate group (negatively charged) one of 4 possible nitrogenous bases (adenine, cytosine, guanine, Uracil)
26
DNA nucleotides 3 components?
Sugar (deoxyribose) phosphate group (negatively charged) one of 4 possible nitrogenous bases (adenine, cytosine, guanine, thymine)
27
Example of nitrogenous base single-ring?
Cytosine, thymine, uracil
28
Example of nitrogenous base double-ring?
Adenine, guanine
29
DNA consists of what?
2 nucleic acid strands coiled around each other
30
RNA consists of what?
Single nucleic acid strand
31
What is cell theory?
Cell is the fundamental unit of life
32
What is a light microscope?
beam of light is passed thru specimens for living cells to be observed.
33
What is a scanning electron microscope?
beam of electrons is passed thru specimen, cells must be dead for details of cell’s outer surface
34
What is Transmission electron microscope?
cells must be dead, with beam of electrons used for cell’s internal structure
35
Why are cells so small?
As cell size increases surface area-to-volume ratio decreases
36
What are all organisms possessing prokaryotic cells?
Unicellular
37
Prokaryotic cells lack what?
Nucleus and other membrane- enclosed organelles
38
What is the nucleoid region?
region of cell where DNA is located
39
What do ribosomes do?
Synthesize proteins using info stored in DNA
40
What does plasma membrane do?
Regulates transport of materials into and out of the cell
41
What does the cell wall do?
Provides structural support
42
What do capsules do?
Provide protections
43
What does pili do?
Allow bacteria to attach to surfaces
44
What does the flagella do?
Enable movement
45
Most organisms possessing Eukaryotic cells are?
Multicellular
46
Examples of multicellular eukaryotes?
Animals, plants, fungi and some protists
47
What do eukaryotic cells possess?
Nucleus and other membrane-enclosed organelles
48
Organelles found in animal cells but not plant cells?
Centrioles, lysosomes, flagella and cilia
49
Organelles found in plant cells but not animal cells?
Cell wall, chloroplasts, cell wall with plasmodesmata
50
2 major Plasma membrane molecules?
Phospholipids and proteins
51
What do short carbohydrate chains attached to phospholipids form?
Glycolipids or glycoproteins
52
Plasma membrane phospholipids contain?
Hydrophobic tail (2 fatty acids) hydrophobic head (phosphate group)
53
What do plasma membranes exist as?
Phospholipid bilayers
54
Peripheral proteins attach to what?
Either the inside or outside of the membrane
55
Integral proteins span across what?
The entire membrane from the inside to the outside of the cell
56
57
The Nucleus is the cell’s what?
Control center
58
What is the structure of the nucleus?
Nuclear envelope, DNA, nucleolus
59
Function of nucleus?
Ribosomes are manufacturer in nucleolus, translation, transcription
60
Ribosomes function where?
Protein synthesis
61
Cytoplasm includes what?
All of cell inside plasma membrane and outside the nucleus
62
What is the endomembrane system?
Many organelles surrounded and connected to each other by membranes
63
Endoplasmic reticulum is what?
A manufacturing organelle
64
What are many attached ribosomes called?
Rough ER
65
What is a smooth ER important for?
Manufacturing of lipids
66
Golgi apparatus is a ?
processing organelles
67
Vacuoles are?
Storage organelles
68
Central vacuole is a?
Large membrane organelle that stores nutrients, wastes, pigments and toxins etc
69
Where are central vacuoles found?
Plant cells
70
What are contractile vacuoles?
Small membranous organelles that store and expel excess water
71
What are food vacuoles?
Small membranous organelles that store food items the cell has ingested
72
What are Lysosomes?
Breakdown organelles filled with digestive enzymes and acids
73
Peroxisomes are what?
Breakdown organelles that contain enzyme catalase
74
What 2 organelles are responsible for converting energy from one form to another within the cell?
Chloroplasts, mitochondria
75
Chloroplasts function?
Organelles that convert solar energy into chemical energy of food- photosynthesis
76
Structure of chloroplasts?
Surrounded by double membrane filled with fluid Stroma
77
Mitochondria does what?
Converts the chemical energy of food into chemical energy of ATP powering cell’s activities
78
What is mitochondria surrounded by?
Double membrane filled with matrix fluid
79
Cytoskeleton is what?
Internal framework of proteins that provides shape and structure to the cell
80
What are microfilaments?
Support cell shape
81
What are microtubules?
Serve as tracks on which organelles are able to move
82
The Flagella and cilia function in what?
Movement
83
What motion propels flagella?
Undulating
84
What motion propels cilia?
Beat-like
85
What does the cell wall provide?
Structure, support and protection
86
What does the extracellular matrix do?
Connect neighboring cells within tissues
87
Who conducted experiments that refuted the idea of spontaneous generation?
Francesco Redi and Louis Pasteur
88
Spontaneous generation is the?
Formation of life from nonliving matter
89
Who hypothesized that organic monomers could form from inorganic molecules under the conditions of earth’s early atmosphere?
Oparin and Haldane
90
Miller and Urey constructed what?
An experimental apparatus to simulate early Earth and test Oparin and Haldane’s hypothesis.
91
What are protocells?
Membranous droplets that maintain an internal composition different from that of their surrounding environment
92
Which comes first DNA or proteins?
DNA
93
RNA molecules are called what?
Ribozymes
94
What do membrane proteins do?
Maintain membrane shape, serve as receptors, bind cells together, act as enzymes, transport materials across the membrane
95
What is selectively permeable?
Plasma membranes
96
Passive transport says?
No energy is required and occurs spontaneously
97
Diffusion is the?
Spreading out of molecules into the available space
98
What is reached once molecules are equally distributed everywhere?
Dynamic equilibrium
99
Molecules move what region of what concentration to what concentration?
Higher; lower
100
Facilitated diffusion is when?
molecules move down their concentration gradient with no energy required
101
Channel proteins allow what?
The passage of ions and small polar molecules such as water
102
Carrier proteins allow what?
The passage of large polar molecules such as glucose and amino acids
103
What two types of transport proteins are involved with facilitated diffusion?
Channel and carrier
104
Osmosis is the diffusion of what?
Water molecules across the plasma membrane
105
Isotonic solutions have what solute concentration and therefore water concentrations?
Equal;equal
106
Hypotonic has what solute concentration and therefore water concentrations?
Lower; higher
107
Hypertonic solutions have what solute concentration and therefore water concentration?
Higher; lower
108
What happens if 2 aqueous solutions are separated by a selectively permeable membrane?
Water will diffuse down its concentration gradient
109
Osmosis results in both solutions becoming?
Isotonic
110
Osmoregulation definition?
Maintaining a proper solute concentration balances water gain and loss by cell.
111
Active transport needed?
Energy and occurs spontaneously
112
Active transport moves molecules from the region of what concentration to the region of what concentration?
lower;higher
113
Active transport protein important in nerve cells?
Sodium-potassium pump
114
Bulk transport is the?
Exit or entrance of very large molecules or many smaller molecules all at once
115
What does bulk transport require?
ATP energy
116
What does exocytosis do?
Bulk transport out the cell
117
What does endocytosis do?
Bulk transport into the cell
118
What is phagocytosis?
Cellular eating engulfing large food particles
119
What is pinocytosis?
Cellular drinking, engulfing large amounts of fluid plus any solutes dissolved in the fluid
120
What is receptor-mediated endocytosis?
Plasma membrane will only fold inward to engulf select molecules that bind to receptor proteins on the membrane
121
Energy is defined as?
Capacity to cause change or perform work
122
Types of energy?
Kinetic, potential
123
Kinetic energy is?
The energy of motion
124
Potential energy is?
The stored energy of location or position
125
What governs energy conversions?
Laws of thermodynamics
126
What is the first law of thermodynamics?
Law of energy conservation- energy cannot be created or destroyed only converted from one form to another
127
What is the 2nd law of thermodynamics?
All energy conversions increase entropy of universe, during any conversion some energy is lost
128
How do cells maintain order?
A decrease in cellular entropy results from an increase in surrounding entropy
129
Chemical energy is the?
Potential energy of atoms bonded within molecules
130
Exergonic reactions are?
Chemical reactions that release energy such as cellular respiration
131
Endergonic reactions are?
Chemical reactions that require energy such as photosynthesis
132
ATP is the?
Molecule directly used for all cellular work
133
For continued cellular work ATP must be?
Restored
134
Energy coupling is the use of energy released during?
Exergonic reactions to drive endergonic reactions
135
Enzymes are?
Proteins that catalyze chemical reactions within cells
136
Anabolism refers to what?
Chemical reactions that build larger molecules from smaller molecules
137
Example of anabolism?
Dehydration Reactions
138
Anabolic reactions are endergonic or exergonic?
Endergonic- they require an input of energy
139
Catabolism refers to what?
Chemical reactions that break down larger molecules into smaller molecules
140
Are catholic reactions exergonic or endergonic?
Exergonic
141
Example of catabolism?
Hydrolysis reactions
142
Activation energy is the?
Energy required by reactant molecules to start the reaction
143
How do enzymes catalyze chemical reactions?
By lowering the amount of activation energy required
144
What is the reactant molecule acted on by the enzyme called?
Enzyme’s substrate
145
What happens to enzymes after the products are released?
They are recycled to catalyze reaction after reaction
146
How are enzymes named?
For the substrate molecules on which they act
147
What happens to enzyme activity as substrate concentration increases?
It increases
148
What happens to enzyme activity as temperature increases?
It increases
149
What does a low or high pH cause to enzymes?
denaturation
150
What are coenzymes?
Non-protein organic molecules that aid enzyme function
151
What is an example of a coenzyme?
Vitamins
152
What are cofactors?
Inorganic ions that aid enzyme function
153
What is an example of a cofactor?
Minerals
154
Enzyme inhibitors are molecules that what?
Disrupt the function of enzymes
155
What are types of enzyme inhibitors?
Competitive and noncompetitive
156
Competitive inhibitors are?
Molecules that have shapes similar to the enzyme’s substrates
157
What do competitive inhibitors do?
They bind to the active site and block the substrate from binding so no chemical reaction occurs
158
What are noncompetitive inhibitors?
They may bind at active allosteric site which induces fit of enzyme before substrate can bind to active site and shape of enzyme and substrate don’t match so no chemical reaction occurs
159
What are examples of enzyme inhibitors?
Antibiotics, pesticides, feedback inhibition
160
Antibiotics are?
Inhibitors of enzymes that build bacterial cell walls
161
What are pesticides?
Inhibitors of insect nervous system enzymes
162
What is feedback inhibition?
If cell has enough product, product acts as inhibitor of enzyme for reaction that produced it
