Exam 1 Flashcards
1
Q
Cell
A
The smallest functional units of matter that form all chemical substances
Cannot be further broken down into other substances by ordinary means
2
Q
Proton
A
positive charge (+)
found in atomic nucleus
3
Q
Neutron
A
neutral
found in atomic nucleus
4
Q
Electron
A
negative charge (−)
found in orbitals
5
Q
What gives an atom a no net charge?
A
Equal # of protons and electrons
Neutrons may vary
6
Q
Orbitals
A
Regions surrounding the Nucleus
7
Q
Covalent
* nonpolar
*polar
A
Sharing of electrons in chemical bonds to fill valence shells
Equally sharing electrons
Unequally sharing electrons
8
Q
Ion
A
atom loses or gains one or more electrons
9
Q
Atomic Number
A
Equal to the number or Protons and Electrons (no net charge)
10
Q
pH (all about it)
A
1-6= acidic
7= neutral
8-…=alkaline
11
Q
Dalton
A
measures atomic mass
(amu)
12
Q
Mole
A
6.022x 10^23 (Avogadro’s number)
13
Q
List the elements that make up most of the mass of all living organisms.
A
carbon, hydrogen, nitrogen, oxygen
14
Q
What is a Compound?
A
Any molecule composed of two or more elements
15
Q
What is a Molecule?
A
group of two or more atoms bonded together
16
Q
Hydrogen bonding
A
Hydrogen atom from one polar molecule is attracted to an electronegative atom from another molecule
17
Q
Isotope
A
Multiple forms of an element that differ in the number of neutrons
18
Q
Solute
A
something dissolved into a solvent
19
Q
Solvent
A
The liquid the solute is dissolved in
20
Q
Molarity
A
the amount of a substance in a certain volume of solution.
21
Q
Hydrophobic
A
“water-fearing”
22
Q
Ionic Bond
A
Electrons are transferred, forming ions that are attracted to each other
23
Q
Octet Rule
A
Atoms are stable when their outer shell is full (8 electrons)
24
Q
Free Radicals
A
*Molecule containing an atom with a single, unpaired electron in its outer shell
*Highly reactive molecules; can “steal” an electron from other molecules
25
Heat of vaporization
Energy to boil
26
Heat of fusion
Energy to melt
27
Colligative properties
Properties that depend strictly on the total number of dissolved solute particles, not on the type of solute
28
Acids
are molecules that release hydrogen ions in solution
(hydrogen peroxide)
29
Bases
Lowers the hydrogen concentration
30
What are the effects of pH
*The shapes and functions of molecules
*The rates of many chemical reactions
*The ability of two molecules to bind to each other
*The ability of ions or molecules to dissolve in water
31
Buffers
help to maintain a constant pH
32
Macromolecules
large, complex organic molecules
33
Functional Groups
Groups of atoms with special chemical features that are functionally important
34
Isomers
Two molecules with an identical molecular formula but different structures and characteristics
35
Structural Isomers
contain the same atoms but in different bonding relationships
36
Stereoisomers
and 2 kinds
identical bonding relationships, but the spatial positioning of the atoms differs in the two isomers
Cis-trans isomers - positioning around double bond
Enantiomers - mirror image molecules
37
What are the Four major types of organic molecules and macromolecules
Carbohydrates
Lipids
Proteins
Nucleic acids
38
Carbohydrates
Composed of carbon, hydrogen, and oxygen atoms
Most of the carbon atoms in a carbohydrate are linked to a hydrogen atom and a hydroxyl group
39
Monosaccharides
Simplest sugars Most common are 5 or 6 carbons
Different ways to depict structures
*Ring
*Linear
40
Disaccharides
Composed of two monosaccharides
Joined by dehydration or condensation reaction
*Glycosidic bond
Examples: sucrose, maltose, lactose
41
Condensation reaction
Links monomers to form polymers
42
Hydrolysis reaction
Polymers broken down into monomers
43
Polysaccharides
Many monosaccharides linked together to form long polymers
Examples:
Energy storage – starch, glycogen
Structural – cellulose, chitin, glycosaminoglycans, peptidoglycan
44
Lipids
*Composed predominantly of hydrogen and carbon atoms, and some oxygen
*Defining feature of lipids is that they are nonpolar and therefore very insoluble in water
*Include fats, phospholipids, steroids, waxes
*Lipids comprise about 40% of the organic matter in the average human body
45
Fats
*Known as triglycerides
*Formed by bonding glycerol to 3 fatty acids
*Joined by dehydration; resulting bond is an ester bond
*important for energy storage
46
Fatty Acids (saturated and unsaturated)
Saturated – all carbons have the maximal amount of hydrogens
Tend to be solid at room temperature
Unsaturated – contain one or more double bonds
Tend to be liquid at room temperature (known as oils)
Cis forms naturally; trans formed artificially
Trans fats are linked to disease
47
Cis
forms naturally
48
Trans
forms artificially
49
Phospholipids
Formed from glycerol, two fatty acids and a phosphate group
Phospholipids are amphipathic molecules
Phosphate head – polar/hydrophilic
Fatty acid tail – nonpolar/hydrophobic
50
Phospholipids with the cell membrane
Phospholipids will form an enclosed sphere, and are critical to the structure of the plasma membrane
51
Steroids
Four interconnected rings of carbon atoms
Usually insoluble in water
Example: Cholesterol
52
Proteins
Composed of carbon, hydrogen, oxygen, nitrogen, and small amounts of other elements, notably sulfur
Building blocks of proteins are amino acids
53
Polypeptide Formation
Amino acids joined by dehydration reaction
54
Primary structure
Amino acid sequence
Determined by genes
Ribonuclease – 124 amino acids
55
Secondary Structure
Chemical and physical interactions cause protein folding
56
Tertiary Structure
Folding gives protein complex 3D shape
This is the final level of structure for a single polypeptide chain
57
Quaternary structure
Made up of two or more polypeptides
Individual polypeptide chains are protein subunits
Protein can be formed from several copies of the same polypeptide
58
What are the 5 factors that promote protein folding and stability?
Hydrogen bonds
Ionic bonds and other polar interactions
Hydrophobic effects
Van der Waals forces
Disulfide bridges – link the –S H groups in two cysteine side chains together
59
Nucleic Acids
Responsible for the storage, expression, and transmission of genetic information
Monomer is nucleotide
60
DNA
Stores genetic information encoded in the sequence of nucleotide monomers
61
RNA
Decodes D N A into instructions for linking together a specific sequence of amino acids to form a polypeptide chain
62
What is the cell theory
All living organisms are composed of one or more cells
Cells are the smallest units of life
New cells come only from pre-existing cells by cell division
63
In Microscopy, what are the 3 important parameters?
Resolution
Ability to observe two adjacent objects as distinct from one another
Contrast
How different one structure looks from another
Contrast can be enhanced by special dyes to reveal cellular structure
Magnification
Ratio between the size of an image produced by a microscope and its actual size
64
Light Microscopy
Uses light for illumination
Resolution 0.2 micrometer
65
Electron Microscopy
Uses a beam of electrons for illumination
Resolution 2 nanometer (100 times better)
66
Standard light microscope
Light is focused with glass lenses
Light passes directly through sample
67
Phase Contrast Microscope
Microscope amplifies differences in phase of light transmitted or reflected by sample
Improved contrast of denser structures
68
Differential interference contrast (D I C or Nomarski microscopy)
Another method using optics to improve contrast
Good for internal cellular structures
69
Transmission Electron Microscope (TEM)
Beam of electrons transmitted through sample
Thin slices stained with heavy metals
Some electrons are scattered while others pass through to form an image
70
Scanning Electron Microscope (SEM)
Sample coated with heavy metal
Beam scans surface to make 3D image
71
Prokaryotes
Simple cell structure
No nucleus
72
Eukaryotes
More complex cells
D N A enclosed within membrane-bound nucleus
Internal membranes form organelles
73
What are the 2 types of Prokaryote cells
Bacteria and Archaea
Bacteria- small cells, very abundant
Archaea- Small cells, less common (found in extreme environments)
74
Nucleoid Region
DNA is located
75
Ribosomes
Synthesize Proteins (make proteins)
76
Plasma Membrane
double layer of phospholipids and embedded proteins; barrier between interior of the cell and external environment
Functions:
Membrane transport in and out of cell, with selective permeability
Cell signaling using receptors
Cell adhesion
77
Glycocalyx
traps water, gives protection, help evade immune system (capsule)
78
Cells have the same DNA, but all have different ______
Proteomes
79
What does surface are have to do with a cell?
As cells get larger, the surface area-to-volume ratio gets smaller. This affects cell function
High surface area/volume ratio required for adequate nutrient update and waste export
80
Cytosol
Region of a eukaryotic cell that is outside the cell organelles but inside the plasma membrane
Cytosol is central coordinating region for metabolic activities of eukaryotic cells
81
Metabolism
* Catabolism
*Anabolism
M- the sum of all the chemical reactions of a cell
C- Breakdown of a molecule into smaller components
A- Synthesis of cellular molecules and macromolecules
82
ATP Synthase
Makes ATP
83
In the Cytoskeleton, what are the 3 types of protein filaments?
Microtubules
Intermediate filaments
Actin filaments
84
Microtubules
Long, hollow, cylindrical structures composed of a- and b-tubulin; have a plus end and minus end
Microtubules important for cell shape and organization; movement of chromosomes
85
Microtubule-organizing center (M T O C)
Site in the Eukaryote where microtubules grow
86
Dynamic Instability
single microtubule can oscillate between growing and shortening phases
87
Intermediate Filaments
*Found in many but not all animal species
*Intermediate filament proteins bind and form ropelike structures – function as tension-bearing fibers that maintain cell shape and rigidity
88
Actin Filaments
Known as Microfilaments
Have plus and minus ends and are dynamic structures
Play a key role in cell shape and strength
In many cells actin filaments support the plasma membrane and provide shape to the cell
89
Motor Proteins
Proteins that use A T P as a source of energy for movement
Three domains— the head, hinge, and tail
90
What are the 3 types of movement of motor proteins?
Motor protein carries cargo along the filament
Motor protein remains in place, the filament moves
Motor protein and filament both restrained – action of the motor protein exerts a force that bends the filament
91
Flagella
Usually longer than cilia
Present singly or in pairs
92
Cilia
Often shorter than flagella
Tend to cover all or part of the cell surface
93
Both Flagella and Cilia do what?
Both flagella and cilia generate movement
Both contain an axoneme containing microtubules, the motor protein dynein, and linking proteins
94
Nuclear Envelope
Double-membrane structure enclosing nucleus
95
Nuclear Pores
where inner and outer nuclear membranes make contact with each other
96
Nuclear Matrix
nuclear lamina and an internal nuclear matrix
Filamentous network
Organizes chromosomes
97
Endoplasmic Reticulum (ER)
*Network of membranes that form flattened, fluid-filled tubules or cisternae
*ER membrane encloses a single compartment called the ER lumen
98
Smooth ER
Lacks ribosomes
Detoxification, carbohydrate metabolism, calcium balance, synthesis, and modification of lipids
99
Rough ER
Studded with ribosomes, Oxidized Enviornment
***Involved in protein synthesis and sorting***
-Glycosylation, Disulfide bridges
100
Transitional ER
Site of Vesicle formation
101
Golgi Apparatus
How do materials move through it?
Stack of flattened, membrane-bounded compartments
Vesicular transport – vesicles bud from one compartment and fuse to the next compartment
Cisternal maturation – cisterna mature from cis to medial to trans
102
Lysosomes
Contain acid hydrolases that perform hydrolysis
103
Autophagy
Recycling of worn-out organelles through endocytosis
104
Vacuoles
Functions are extremely varied, and they differ among cell types and environmental conditions
Central vacuoles in plants for storage and support
Contractile vacuoles in protists for expelling excess water
Phagocytic vacuoles in protists and white blood cells for degradation
105
Peroxisomes
Catalyze certain reactions that break down molecules by removing hydrogen or adding oxygen
106
Semiautonomous Organelles
*Mitochondria and chloroplasts
*Grow and divide to reproduce themselves
*They are not completely autonomous because they depend on the cell for synthesis of internal components
107
Mitochondria
Make ATP
Also involved in the synthesis, modification, and breakdown of several types of cellular molecules
108
Photosynthesis
Capture light energy and use some of that energy to synthesize organic molecules such as glucose
109
Nuclear Genome
chromosomes in the nucleus
110
Endosymbiosis
smaller species lives inside larger species
111
What is protein sorting?
*Eukaryotic proteins are sorted to the right destination
*Most eukaryotic proteins contain short amino acid sequences that serve as sorting signals
*Remain in cytosol
*Cotranslational sorting
*Post-translational sorting
112
Cotranslational sorting
Begins in cytosol during translation
E R signal sequence bound by signal recognition particle (S R P) and associates with E R channel
Second step in cotranslational sorting
Vesicle buds from E R membrane and fuses with the target membrane and protein is delivered
113
Post translational Sorting
Synthesized in cytosol and taken up by target organelle
Short amino acid sequence directs the protein to its target where it is taken up from the cytosol
Proteins called chaperones can keep a protein in an unfolded state
114
Systems Biology
the study of how new properties of life arise from complex interactions of its components
115
Fluid Mosaic Model
*Membrane is considered a mosaic of lipid, protein, and carbohydrate molecules
*Membrane resembles a fluid because lipids and proteins can move relative to each other within the membrane
116
FFEM
Freeze fracture electron microscopy, specialized form of TEM, can be used to analyze the interiors of phospholipid bilayers
117
