Chemistry/Physiology Recap Flashcards
(170 cards)
1
Q
Chemical energy
A
- Stored in bonds of chemical substances
- ex. Glucose (C6H12O6)
The energy is stored in the covalent bonds between carbon atoms
2
Q
Some bacteria require energy in the form of the _______________.These bacteria cannot manufacture food like ___________ nor absorb nutrients from the environment like _________.
A
- Organic Molecules
- photosynthetic organisms
- fungi
3
Q
The organic ___________ some bacteria take up are broken down to make _______.
A
- molecules
- ATP
4
Q
________ provides the energy cells need to stay alive.
A
ATP (Adenosine Triphosphate)
5
Q
_________ in molecules is stored in the ___________between _________ that make up the molecules.
A
- energy
- bonds
- carbon atoms
6
Q
definition of chemistry
A
Chemistry is the study of interactions between atoms and molecules
7
Q
definition of atom
A
The atom is the smallest unit of matter and cannot be subdivided into smaller substances
8
Q
Atoms interact to form ___________.
A
molecules
9
Q
Atoms are composed of ____________.
A
subatomic particles
10
Q
what are the 3 subatomic particles?
A
Protons, neutrons, electrons
11
Q
Protons
A
positively charged particles found in the nucleus of an atom.
12
Q
Neutrons
A
neutrally charged particles found in the nucleus of an atom.
13
Q
Electrons
A
negatively charged particles that orbit nucleus in an electron cloud
14
Q
A
planetary model of an atom
15
Q
A
orbital model
16
Q
what are the 3 smallest elements?
A
- hydrogen
- helium
- lithium
17
Q
A
- hydrogen (H)
- 1 proton, 0 neutrons, 1 electron
18
Q
A
- helium atom (He)
- 2 protons, 2 neutrons, 2 electrons
19
Q
A
- lithium atom (Li)
- 3 protons, 4 neutrons, 3 electrons
20
Q
outer layer of e- is called the ________, and the e- in that layer are called __________.
A
- valence shell
- valence electrons
21
Q
Only ___________are involved in ____________between any two atoms.
A
- valence electrons
- chemical bonding
22
Q
what are the 4 chemically reactive elements?
A
- hydrogen
- carbon
- sodium
- oxygen
23
Q
Most atoms chemically combined with other atoms to form __________________.
A
molecules and compounds
24
Q
definition of a molecule
A
Two or more atoms bonded together (e.g., H2 or C6H12O6)
25
what is special about valence chemically reactive elements?
* Their valence shell is not full they tend to gain, lose, or share electrons (form bonds) with other atoms to achieve stability
26
Electrons in valence shell (outermost electron shell); __________________ and \_\_\_\_\_\_\_\_\_\_\_\_\_\_
* Have most potential energy
* Are chemically reactive electrons
27
Octet rule (rule of eights)
Except for the first shell (full with two electrons) atoms interact to have eight electrons in their valence shell
28
single covalent bond
* one pair of electrons is shared between atoms
* ex. methane gas= CH4
29
double covalent bond
* two pairs of electrons are shared between atoms
* ex. oxygen gas O2
30
Triple covalent bond
* Three pairs of electrons are shared between atoms
* ex. Nitrogen gas
31
When two or more atoms join together to form molecules, the atoms form \_\_\_\_\_\_\_\_\_\_\_\_.
* Chemical bonds that hold them togther
32
What are the 3 major types of chemical bonds?
* Covalent bonds
* Ionic bonds
* Hyrogen bonds
33
What are the 2 types of covalent bonds
1. polar covalent bonds
2. non-polar covalent bonds
34
Covalent Bonds
* Prefix “co” means “together”, as in cooperate (work together) or cohabitate (live together); “valent” refers to valence e- (in the outermost shell or layer).
* “covalent” means sharing e- pairs together in the valence shell. Keeping in mind the Octet Rule, in which the atoms are trying to make their valence shell “full”, one way to accomplish this is for two atoms to share e- pairs. If one atom shares one e- and the other atom shares another e-, then both atoms have the e- they want to complete their valence shell.
* Covalent bonds - Formed by sharing of two or more valence shell electrons such that each atom fills its valence shell at least part of the time
35
Non-polar covalent bond
* Electrons shared equally \> nonpolar covalent bond
* Produces electrically balanced, nonpolar molecules such as CO2
* charge is balanced among atoms
* Carbon dioxide (CO2) molecules are linear and symmetrical. They are nonpolar
36
Polar Covalent bond
* Unequal sharing of electrons \> polar covalent bond
* Atoms in bond have different electron-attracting abilities
* usually occurs with electronegative elements like oxygen or nitrogen.
* slight negative charge at one end of molecule and slight positive charge at the other end.
37
Electronegative
* oxygen and nitrogen are electronegative
* Strong electron-attracting ability
* Shares e- unequally with other atoms
* V-shaped water (H2O) molecules have two poles of charge—a slightly more negative oxygen end (d–) and a slightly more positive hydrogen end (d+).
38
Ionic bond
* complete transfer of electrons
* separate ions (charged particles) form
* ex. Na+ Cl-
* Transfer of valence shell electrons from one atom to another forms ions; Again, the transfer occurs so that both atoms fulfill the Octet Rule. It is easier for Na atoms to give up one e- than to gain 7 e-; similarly, it is easier for Cl to gain 1 e- than to lose 7 e-.
* One becomes an anion (negative charge), an atom that gained one or more electrons; One becomes a cation (positive charge), an atom that lost one or more electrons; Attraction of opposite charges results in an ionic bond
39
Hydrogen bonds
* Attractive force between hydrogen (usually δ+) of one molecule and an electronegative atom of another molecule or another atom in the same molecule
* Not true bond \> no transfer or sharing of e- (but it is an attractive force between atoms)
* Hold individual water molecules together; gives water important properties for life (universal solvent, resistant to temp changes, cohesion and adhesion, evaporative cooling)
* H bonds also hold large molecules in their three-dimensional shape by acting as intramolecular bonds
* The slightly positive ends (d+) of the water molecules become aligned with the slightly negative ends (d–) of other water molecules.
40
Hydrogen bonds hold individual water molecules together (what kind of bond holds atoms together in a single water molecule?)
Polar covalent bonds
41
Hydrogen bonds gives water properties which are important for life, what are they?
1. universal solvent
2. resistant to temperature changes
3. cohesion and adhesion
4. evaporate cooling
42
Water is the universal solvent, what does that mean?
* it dissolves MANY substances
* water molecules surround the atoms of the substance being dissolved, forming “hydration spheres” around the atoms or parts of the molecules being dissolved. When forming hydration spheres around atoms, the partially negative O atoms in water molecules will point toward the positively charged atoms of the substance being dissolved (Na+ ions, in this case), and the partially positive H atoms will point toward the negatively charged atoms of the substance being dissolved (Cl- ion, in this case). In many cases, the substance is invisible once dissolved, but you still know it is present in the water (dissolved) because you can taste or smell it.
43
Chemical reactions
* Chemical reactions occur when chemical bonds are formed, rearranged, or broken.
* Represented as chemical equations using molecular formulas
* Chemical equations contain: Reactants (Number and kind of reacting substances), and Product(s)
44
Synthesis Reactions
* A + B ----\> AB (e.g. 2H2 +O2 ----\> 2H2O)
* Atoms or molecules combine to form larger, more complex molecule
* Always involve bond formation (Anabolic)
* reactants come togther to make a product
45
Decomposition Reactions
* AB ® A + B (e.g. NaCl à Na+ + Cl- )
* Molecule is broken down into smaller molecules or its constituent atoms
* Reverse of synthesis reactions
* Involve breaking of bonds (Catabolic)
* reactant is broken down into products
46
Exchange Reactions
* AB + C \> AC + B (e.g. Zn + 2 HCl à H2 + ZnCl2 )
* Also called **displacement reactions**
* Involve both synthesis and decomposition
* Bonds are both made and broken
47
Rate
how quickly reactants are formed into products, regardless of the type of reaction.
48
The rate of chemical reactions are affected by:
1. Temperature (increased temp, increased rate)
2. Concentration of reactant (increase concentration, increased rate)
3. Particle size (decreased particle size, increased rate.
4. Catalysts increase Rate without being chemically changed or part of product
•Enzymes are biological catalysts
49
Chemical reactions are essential for all cells all the time!! Most do not occur naturally at a fast enough rate to provide products needed to stay alive. _____________ inside our cells are crucial for making the reactions occur fast enough to sustain life.
Enzymes
50
molecular weight
The sum of the atomic weights in a molecule is the molecular weight
51
One \_\_\_\_\_\_\_\_of a substance is its molecular weight in \_\_\_\_\_\_\_\_\_\_\_.
* mole
* grams
* ex.
H2O
2H = 2 x 1 = 2 (2 hydrogen molecules times its molecular weight)
O = 16 (1 oxygen molecule's molecular weight)
MW = 18 (moleclar weight of both)
1 mole weighs 18 g
52
cells contain about \_\_\_\_\_\_\_in the cytoplasm and are generally “bathed” in \_\_\_\_\_\_\_\_\_\_.Therefore all reactions are taking place in what we call an _______________ and for the most part all components of that reaction, including reactants, enzymes, and products, are _______ in water.
* 75% water
* watery fluid
* aqueous or watery enviornment
* dissolved
53
Solution
* Solvent (liquid) + solute(s) (dissolved particles), e.g. Kool Aid (water is solvent, Kool Aid powder and sugar are dissolved solutes)
* Solutions are often described in terms of their **CONCENTRATION**, or the amount of solute dissolved.
* In chemistry, this was sometimes referred to as **molarity or molar concentration**. The higher the molarity, the more solute per given volume of solvent
54
pH
is a measure of [hydrogen ion]
55
The pH scale ranges from \_\_\_\_\_\_\_.
0-14
56
a pH of 0-6.99 is \_\_\_\_\_\_\_.
acidic
57
a pH of 7.00 is \_\_\_\_\_\_\_\_.
neutral
58
a pH of 7.01-14.0 is \_\_\_\_\_\_\_.
basic
59
a pH scale is \_\_\_\_\_\_\_\_\_\_\_. A pH 5 solution is \_\_\_\_times more acidic than a pH 6 solution and \_\_\_\_\_\_\_times more acidic than a pH 7 solution
* logarithmic
* 10
* 100
60
Another important aspect of the environment in which chemical reactions occur is the pH (“power of Hydrogen”). pH is important because it affects the \_\_\_\_\_\_at which chemical reactions occur, and must be _________ in order for the body to function properly.
* rate
* homeostatic
61
Acids are \_\_\_\_\_\_\_donors.
* proton
* Release H+ (a proton, or hydrogen ion) in solution
* HCl \> H+ + Cl–
* HCl, HC2H3O2 (HAc), and H2CO3
62
Bases are proton \_\_\_\_\_\_.
* acceptors
* Take up H+
* Na+ + OH–
* OH– accepts an available proton (H+)
* OH– + H+ à H2O
* Bicarbonate ion from solution (HCO3–)
* NaOH and ammonia (NH3)
63
relative free [H+] of a solution is measured on the \_\_\_\_\_\_\_\_\_\_\_.
* pH scale
64
As [OH-] decreases and [H+] increases...
* acidity increases
* pH lowers
65
As free [H+] decreases.....
* alkalinity increases
* [OH–] increases as [H+] decreases
* pH increases
66
Functional groups
Functional groups bond to carbon skeletons and are responsible for most of the chemical an physical properties of a particular organic compound
67
Name this group, why is it impotant biologically?
* Alcohol
* lipids and carbohydrates
68
Name this group, why is it important biologically?
* Aldehyde
* reduces sugars such as glucose; polysaccarides
* in and aldehyde molecule the carbon oxygen double covalent bond is on the end of the molecule.
69
Name this group, why is it important biologically?
* Methyl
* DNA; and energy metabolism
70
Name this group, why is it important biologically?
* Ketone
* metabolic intermediates
* the carbon oxygen double covalent bond is located inside the molecule instead of at the end
71
Name this group, why is it important biologically?
* Amino
* Proteins
* can also be written NH2
72
Name this group, why is it important biologically?
* Ester
* bacterial and eukaryotic plasma membranes
73
Name this group, why is it important biologically?
* Ether
* Archaeal plasma membranes
* the O, 2 Cs and the 4 Hs
74
Name this group, why is it iportant biologically?
* Sulfahydrl
* energy metabolism and protein structure
* can also be SH
75
Name this group, why is it important biologically?
* Carboxyl
* organic acids, lipids and proteins
76
Name this group, why is it important biologically?
* Phosphate
* DNA; ATP
77
Identify the functional groups in an amino acid.
1. Amino group
2. Hydrogen
3. Carboxyl group (acid group)
4. Some form of functional group (replaceable)
\*An amino acid can be made polar or nonpolar by different functional groups.
78
What do amino acids make?
proteins
79
What are the types of chemical reactions?
1. **Dehydration synthesis**
- Anabolic reaction; builds a dimer, how polymers are made.
- Endergonic reaction; uses up energy
- Monomers form covalent bonds when OH is removed from one monomer and H is removed from the other (at bonding site).
- Chemical water is removed to make a covalent bond.
2. **Hydrolysis**
- Catabolic reaction; breaks down polymers into monomers.
- Exergonic reaction; releases energy
- The covalent bonds between monomers are broken apart by a water molecule; OH is added to one monomer and H is added to the other monomer.
80
to find out how many water molecules are made during a dehydration synthesis reaction what do you do?
* subtract 1 from the total amount of monomers in the polymer and the answer is the amount of water molecules made
* 100 monomers in a polymer ----\> 100 - 1= 99
* 99 water molecules were made
81
how do you find out how many water molecules were used to slipt up a polymer into monomers?
* it takes 1 water molecule to spilt up a covalent bond between 2 monomers.
* OH bonds with one molecule and H bonds with the other- catabolic
* To break up 100 monomers you need 99 water molecules.
82
How do you tell different macromolecules apart?
* the elements that make up the molecule
* the ratio of thos elements
83
What are the 4 organic macro molecules?
1. Carbohydrates
2. Proteins
3. Lipids
4. Nucleic acids
These are all polymers
84
85
carbohydrates
Function: dietary energy; storage and plant structure
Monomer form: Monosaccharide
Examples: Monosaccharides: glucose, fructose,
Dissaccharides: lactose, sucrose
Polysaccharides: starch and cellulose
\* carbohydrates are used in bacteria capsules allows bacteria to avoid immune cells\*
86
Lipids
Function: longterm energy storage (for fats); hormones (for steriods)
Monomer: fat molecule made of glycerol (Hydrophilic) and fatty acid tail (Hydrophobic).
Examples: fats, oils, steriods.
\*bacteria do not store lipids, they metabolize them to include it in their membrane\*
87
Proteins
Functions: Enzymes, structure, storage, contraction, transport, etc.
Monomer: Amino acid
Examples: lactase (enzyme), hemoglobin
\*proteins are the the only macromolecules can contain sulfur.\*
88
Nucleic acids
Functions: information storage
Monomer: nucleotide
Examples: DNA and RNA
89
What molecules are being shown?
monosaccharides
90
what molecule is bing shown?
disaccaride
91
what molecules are being shown?
Polyschaccarides
92
what molecule is this?
* amino acid
* many amino acids bonded togther make a polymer (polypeptide chain or protein)
93
what molecule is this?
* fat molecule; glycerol and fatty acids
* many fat molecules bonded togther make lipids (polymer)
94
what molecule is this?
* nucleotide
* many nucleotides bonded togther form nucleic acids; DNA or RNA (polymers)
95
Dehydration synthesis and Hydrolysis work the same for all macromolecules?
True
96
bacteria do not store glucose as \_\_\_\_\_\_\_\_\_\_\_.
glycogen
97
Triglyceride
1 glycerol plus 3 fatty acid chains; waters removed to make it
98
what does it mean if you see OH bonded on a molecule?
it can be dissolved in water.
99
why don't lipids dissolve in water?
because they have no OH groups ; which means no polarity which means the fat molecules cannot hydrogen bond with water.
100
The formation of a fat molecule is accomplished through.
dehydration synthesis
101
The polar phosphate group in the head of a phospholipid molecule allows it to do what?
allows the outer and inner aspect of the cell to interact with watery eviornments in the ECF and cytoplasm.
102
what is the fluidity in the phospholipid bilayer, the property that makes the mosaic model possible.
the fluidity is caused by a bent unsaturated fatty acid chain; double bonds between 2 carbons, hydrogens are missing making it "unsaturated" with hydrogens.
103
\_\_\_\_\_\_\_\_\_\_\_\_ make up the bilayer in cell membranes.
* phospholipids
104
Bacteria do not tend to have ________ in their \_\_\_\_\_\_\_\_\_\_\_\_\_.
* cholesterol
* membranes
105
Cholesterol is the basis for all \_\_\_\_\_\_\_\_\_\_in the body.
* steriods
106
in addition to fats lipids also include ___________ because it is \_\_\_\_\_\_\_\_\_\_.
* cholesterol
* non-polar
107
what type of molecule is this? How can you tell?
* A steriod hormone (testosterone)
* four interlocking hydrocarbon rings form a steroid.
108
what is the bond between 2 amino acids called?
peptide bond
109
* This is a poly peptide chain, a polymer of amino acids bonded togther by peptide bonds.
1. R group
2. Peptide bond
3. Amino terminus (unbonded amine group)
4. Carboxyl terminus (unbonded caboxyl group) (acid group)
110
proteins have a begining and \_\_\_\_\_\_.
end
111
peptide bonds between 2 amino acids make \_\_\_\_\_\_\_.
poly peptide chains (proteins)
112
Primary structure
* when amino acids form a poly peptide chain (amino acid sequence)
* caused by peptide bonds between amino acids
* the number of amino acids and the sequence of amino acids determine primary structure, shape and ability to function and interact with other molecules; shape determines function
* the special ribosomes of bacteria are the target of certain antibiotics. Protein synthesis disruption is the goal
113
Phospholipids: The “tails” are nonpolar and therefore do not _________________ Note that equal sharing of ______ among the carbons and hydrogens in the fatty acid tails creates the physical barrier of cell membranes, allowing cells to regulate what \_\_\_\_\_\_\_\_\_\_\_\_\_\_.
* dissolve or interact with water
* electrons
* goes in and out of the cell
114
secondary structure
* the polypeptide chain forms alpha helices (spirals) or beta pleted sheets.
* hydrogen bonding between hydrogens and oxygens on amino acids cause spiraling and folding to occur.
115
what is the job of cholesterol in the phospholipid bilayer?
to control how fluid the membrane is
116
what determines the function of a protein?
it's structure level
117
two peptides bonded togther
dipeptide
118
How many amino acids are there?
20
119
the R group of an amino acid does what?
The R group gives each amino acid unique qualities, such as polarity (allows it to hydrogen bond with other R groups in the protein), electrical charge (allows amino acid's R group to have an ionic bond with other R groups in the protein)
120
Tertiary structure
* R group interaction cause further folding which results in tertiary folding.
* R group interactions:
* ionic bonds
* covalent bonds (disulfide bridges)
* hydrogen bonds
* hydrophobic interactions
* All proteins have a primary, secondary and tertiary structures.
* the secondary structured protein folds on itself again and forms a globular molecule held togther by the abovementioned bonds
* the inner most part of the globular molecule is hydrophobic and the outer most part is hydrophilic (hydrophobic packing)
121
Quaternary structure
* not all proteins have quaternary stucture
* two or more polypeptide chains (subunits) in tertiary structure come togther to create a protein with a quaternary structure (a functional protein)
* the same R group interactions in tertiary proteins cause quternary proteins to be formed
* ionic bonds
* covalent bonds
* Hydrogen bonds
* hydrophobic interactions
* Examples: Hemoglobin and collagen
* 4 subunits= tetromer 3 subunits= trimer
* 2 subunits= dimer
122
proteins can be come denatured what does this mean and how does it happen?
* protein loses its shape which effects its function
* this happens whenproteins are exposed to high temperatures or low pH
123
Enzymes
* proteins that catalyze chemical reactions in living things
* Enzymes make it easier for reactions to happen (less energy needed) ----\> easier and faster to make and break chemical bonds.
124
how enzymes work
* enzymes are proteins so their shape is specific for their job
* subtrates bind to active sites on an enzyme forming a enzyme-substrate complex. (the enzyme's shape changes
* the enzyme positions the substrates to were the atoms can interact with eachother
* when the bond is formed or broken (dehydration synthesis or hydrolysis) the substrates or products are released; the enzyme returns to it original shape. ready to aid more chemical reactions
125
DNA and RNA are \_\_\_\_\_\_\_\_\_\_.
nucleic acids
126
the monomer of a nucleic acid
nucleotide
127
what are the parts of a nucleotide?
1. sugar-phosphate backbone
2. Nitrogenous base (purine or pyrimidine)
* Adenine- pyrimidine
* Thymine (DNA)- purine
* Cytosine- purine
* Guanine-pyrimidine
* Uracil (RNA) - purine
128
Nucleotide monomers are bonded together in long chains by _________________ (what type of reaction breaks them apart?)
* dehydration synthesis reactions
* hydrolysis reactions
129
What is the difference between RNA and DNA?
* in DNA two polynucleotide (made of covalently bonded nucleotides) strands are hydrogen bonded and twisted into a helix shape.
* RNA is made up of only 1 polynucleotide strand.
* the sugars that make up the sugar-phosphate backbone differ-
* RNA: Ribose
* DNA: Deoxyribose
130
What are the 2 different types of nucleotides? what makes them different?
* purines- 2 rings
* pyrimidines- 1 ring
131
A (adenine) and G (guanine) are \_\_\_\_\_\_\_\_\_.
purines
132
T (thymine) and C (cytosine) and U (uracil) are \_\_\_\_\_\_\_\_\_\_\_\_\_.
pyrimidines
133
ATP is a \_\_\_\_\_\_\_\_\_
* Nucleotide
* provides energy for cells
* made up of adenine, ribose and 3 phosphate groups
134
what makes ATP such a great energy source?
phosphate bonds are high in energy; when the bonds are broken down by hydrolysis it releases the energy pent up between electrons from oxygen molecules who have like charge repulsion and want to get away from eachother.
135
A....T what do the "....." represent?
hydrogen bonds
136
Purines always H bond with \_\_\_\_\_\_\_\_\_\_\_.
* pyrimidines
* the opposite is true
* A-T or U
* G-C
137
ATP _____________ proteins or reactants to allow \_\_\_\_\_\_\_\_\_\_, \_\_\_\_\_\_\_\_, provide \_\_\_\_\_\_\_These are all functions needed to maintain life.
* phoshorylates
* substances to be transported
* muscle cells to contract
* energy.
* waste removal
138
Base pair rules
* the specific way in which nucleotides H bond with eachother
* The rules of base pairing (or nucleotide pairing) are: A with T: the purine adenine (A) always pairswith the pyrimidine thymine (T) C with G: the pyrimidine cytosine (C) always pairs with the purine guanine (G)
139
Each strand of DNA has a ________ based on the numbering of the \_\_\_\_\_\_\_\_\_\_.
* direction
* carbon atoms
140
antiparallel
The two strands run in opposite directions
141
cells cannot use food molecules (monomers directly) they have to under go processing in the _________ to form ATP; a molecule that cells can use to do work.
* krebs cycle
142
ATP is actually a nucleotide, with three phosphate groups attached. Release of the third phosphate group provides energy for cellular work, and results in \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. The chemical reaction is as follows: ATP ----\> ADP + P
The reaction is also reversible; energy from food molecules is used to ______________ onto ADP to form ATP (the reaction is: ADP + P -----\> ATP)
* ADP (Adenosine triphosphate) and inorganic phosphate
* Add phosphate back
143
As long as ATP is available, cells continue to perform their functions, and \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
* microorganism remains alive.
144
atomic number
number of protons in nucleus
145
Describe the structure of an atom and its relation to the physical properties of elements.
* **nucleus** made up of protons and neutrons
* electrons move around nucleus in **electron shells**
* same amt of protons and electrons
* the **chemical properties** of an atom rely mostly on the **number of electrons in its outer shel**l.
146
atomic weight
the number of protons and neutrons in an atom added togther
147
electrons are arranged in _________ around atoms.
electron shells
148
electron configuration
* electron configuration is the distribution of electrons of an atom in atomic or molecular orbitals.
* shells of electrons layered outward away from the nucleus
* innermost shell carries 2, second shell carries 8 and the third shell (valence shell) carries 8
149
atoms can give up share or accept electrons in its valence shell in order to...
* become chemically stable
* Octet rule; each valence shell wants 8 e- ; so the closer a atom is to having 8 e- the more reactive it is.
150
How do atoms form molecules?
* through chemical bonding:
* ionic bonds
* covalent bonds
* hydrogen bonds
151
Why do molecules stay togther?
because the valence electrons of the combining atoms undergo chemical bonding
152
why do chemical bonds contain energy?
because energy is needed to form chemical bonds. chemical bonds hold potential energy.
153
ion
negatively (anion) or positively charged atom or group of atoms (by gaining or losing electrons)
154
ionic bond
an attracton between 2 atoms; one with a positive charge resulting from the lossof e- and one with a negative charge resulting from the gain of an e-
155
mole
the molecular weight of a substance in grams
156
molecular weight
the atomic weights of a molecule's atoms added togther.
157
List several properties of water that are important to living systems.
* high boiling point, and low freezing point
* hydrogen bonds between water molecules affects density.
* universal solvent
* Water is a reactant or product in many chemical reactions. (important source of hydrogen and oxygen)
158
what pHdo most bacteria grow best in?
6.5-8.5 pH
159
the ratio of H to O atoms in a carbohydrate is
2:1
160
what is the general formula for carbohydrates
CH2O
161
simple lipids
* fats or triglycerides
* contain and alcohol called glycerol
* plus fatty acids
162
Complex lipids
* contain
* nitrogen
* phosphorus
* sulfur
* in addition to carbon, hydrogen and oxygen
* example of a complex lipid is a **phospholipid. made up of a glycerol 2 fatty acids and in the place of the 3rd fatty acid a phosphate group.**
* phospholipids build membranes
* phospholipids have polar and non polar regions
163
Cholesterol
* four fused carbon rings
* OH group attached to ring A makes it a sterol (cholesterol)
* separate fatty acid chains and prevent them from sticking togther in low temperatures; prevents plasma membrane from becomming rigid.
164
Proteins
* contain
* carbon
* hydrogen
* oxygen
* nitrogen and sometimes sulfur
* responsible for many different structure and function roles in a cell.
* Enzymes- speed up chem reactions in cells
* Transporter proteins- on surface of plasmamembran transport substances in and out of the membrane.
* bacteriocins- poisins bacteria make to kill other bacteria
* exotoxins- produced by some microbes
* hormones
* contraction and movement
* antibodies
165
peptide
4-9 amino acids
166
polypeptide
10-2000 or more amino acids
167
168
what does a nucleotide consist of?
* nitrogenous base (purine or pyrimidine)
* Pentose sugar
* phosphate group
169
How do DNA and RNA differ?
* RNA is single stranded
* contains ribose instead of deoxyribose
* contains uracil instead of thymine
* RNA aids in protein synthesis and DNA is responsible for storing determining genetic information.
170
What is ATP made of?
* adinine
* ribose
* 3 phosphate groups bonded to eachother and the ribose molecule
