Purple Pages Flashcards
1
Q
What is a hypothesis?
A
a tentative explanantion for an observation, phenomenon, or scientific problem that can be tested by further investigation.
2
Q
What are 2 properties of a hypothesis?
A
- It must be testable.
- It must be falsifiable. (through observation or experimentation, you must be able to show that your original hypothesis may not be correct.
3
Q
What is a control in an experiment?
A
a set of individuals that will not be subject to the treatment.
4
Q
What is a variable in an experiment?
A
The 1 thing you change in an experiment that you want to test.
5
Q
What are replicates in an experiment?
A
multiple subjects that receive either the same experimental treatment or the same control treatment.
6
Q
What is a scientific theory?
A
a scientifically acceptable, well substantiated explanatoin of some aspect of the natural world. - Refers to concepts that have withstood the test of many experiements.
7
Q
What is the SI base unit of length?
A
Metre (m)
8
Q
What is the SI base unit of mass?
A
kilogram (kg)
9
Q
What is the SI base unit of time?
A
second (s)
10
Q
What is the SI base unit of electric current?
A
ampere (A)
11
Q
What is the SI base unit of temperature?
A
Kelvin (K)
12
Q
What is the SI base unit of the amount of substance?
A
mole (mol)
13
Q
What is the SI base unit of luminous intensity?
A
candela (cd)
14
Q
What are the SI prefix names from 109 to 100
A
giga 109
mega 106
kilo 103
hecto 102
deca 101
15
Q
What are the SI prefix names from 100 to 10-9
A
deci 10-1
centi 10-2
milli 10-3
micro 10-6
nano 10-9
16
Q
What is the SI unit for force?
A
Newton (kg⋅m/s2)
17
Q
What is the SI unit for pressure?
A
Pascal (N/m2)
18
Q
What is the SI unit for energy and work?
A
Joule (J)
19
Q
How is matter defined?
A
Any substance in the universe that has mass and occupies space.
20
Q
What is an element?
A
a pure substance composed of only one type of atom.
21
Q
How is the Atomic Number determined?
A
by how many protons in the nucleus of the atom.
22
Q
How is the Atomic Mass determined?
A
by the total number of protons and neutrons in the nucleus.
23
Q
What is an isotope?
A
An atom with a different number of neutrons in the nucleus
24
Q
What is an unstable isotope called?
A
radioisotope
25
What is the half-life of a radioisotope?
the length of time it takes for one-half of a sample of a radioisotope to decay. Radioactice decay occurs at a steady, clocklike rate for each type of radioisotope.
26
what is a compound?
a substacne the contains two or more elements.
27
What is a molecule?
a group of atoms held together in a particular order through covalent bonds.
28
which bonds dissociate more easily in an aqueous environment - ionic or covalent?
ionic
29
What is electronegativity?
The measure of an atom's attraction for the electrons it shares in a chemical bond with another atom.
30
What is a polar covalent bond the result of?
the unequal sharing of electrons between two atoms that differ in electrongativity.
31
What does this symbol mean?
δ−
partial negative charge
32
What does this symbol mean?
δ+
partial positive charge
33
What is hydrophilic?
water - preferring
34
What is hydrophobic?
water - avoiding
35
What are Van der Waals forces?
weaker than hydrogen bonds
develpp between non-polar molecules or regions of molecules when, through their constant motion, electrons accumulate by chance in one part of a molecule or another. Leads to zones of positive and negative charge making the molecule polar.
36
Why does ice float?
because the hydrogen bonds of the water lattice is further spaced apart when water freezes (ice lattice) making it about 10% less dense than water.
37
What is cohesion in relation to water?
The hydrogen-bond lattice of water results in water molecules staying together (cohesion)
38
What is surface tension?
The measure of how difficult it is to stretch or break the surface of a liquid.
39
What is a hydration shell?
A surface coat of water. Becasue water molecules are small and strognly polar, they redily surround other polar and charged molecules and ions. It reduces the attraction between the molecules or ions and promotes their separation and entry into a solution.
40
What is concentration of a solution?
The number of molecules or ions of a substance in a unit volume of space, such as 1 mL or 1 L
41
What is the dissocation of water and how does it relate to pH?
Dissociation is the ability to separate. Water will dissociate into hydronium ions and hydroxide ions.
In pure water, there will be equal parts H+ and OH- ions for a pH of 7. Adding other substances can alter teh concentrations of the ions making it either acidic or basic.
42
How do you calculate pH?
pH = -log10[H+]
43
Why is acidity important in cells?
because even small changes (0.1 or 0.01) in the pH unit can drastically affect biological reactions.
44
How do living organisms control the internal pH of their cells?
Buffers - substances that compensate for pH changes by absorbing or releasing hydrogen ions. Weak acids or weak bases
45
What are organic molecules?
molecules based on carbon.
46
What are the four major classes of organic biological macromolecules?
carbohydrates
lipids
proteins
nucleic acids
47
What is dehydration synthesis or a condensation reaction?
when the components of a water molecule are removed during a reaction, usually as part of the assembly of a larger molecule from smaller subunits.
48
What is hydrolysis?
The components of a water molecule are added to functional groups as molecules are broken into smaller subunits.
49
What are functional groups?
The reactive groups attached to organic molecules.
50
What are the most common functional groups in biological reactions?
hydroxyl
carbonyl
carboxyl
amino
phosphate
sulfhydryl
51
What is a hydroxyl group?
-OH
They are polar
Enables an alcohol to form linkages to other organic molecules through dehydration synthesis reactions
52
What is a carbonyl group?
C=O
reactive parts of aldehydes and ketones
act as major building blocks for carbohydrates and take part in the reactions supplying energy for cellular activities
53
What is a carboxyl group?
-COOH
the functional group of organic acids.
gives organic molecules acidic properties because its -OH group readily releases the hydrogen as a proton (H+) in solution.
54
What is an amino group?
-NH2
linked to an R group on the other side of amino acids.
55
What is a phosphate group?
-OPO3-2
The phosphate group is the nucleic acid DNA.
They are added to or removed from biological molecules as part of reactions that conserve or release energy.
The activity of many proteins is turned on or off by the addition or removal of phosphate groups.
56
What is a sulfhydryl group?
-SH
easily converted into a covalent linkage in which it loses its hydrogen atom as it binds. In many of these linking reactions, two sulfhydryl groups interact to form a disulfide linkage. In proteins, the disulfide bond contributes to tertiary structure.
57
What are carbohydrates?
The most abundant biological molecule.
Act as the major fuel substances providing chemical energy for cellular activity.
contain carbon, hydrogen, and oxygen atoms in the ratio 1C:2H:1O
occur as either monosaccharides or chains of monosaccharides linked together.
58
What are the properties of monosaccharides?
soluble in water
most are sweet
The most common in living organisms are:
3 carbons (trioses)
5 carbons (pentoses)
6 carbons (hexoses)
can occur in linear form
those with 5 or more carbons can fold back on themselves to assume a ring form.
59
What are disaccharides?
assembled from two monosaccharides
linked by a dehydration synthesis reaction with glycosidic bonds
Maltose, sucrose and lactose are common disaccharides
60
What are polysaccharides?
longer chains formed by the end-to-end linking of monosaccharides through dehydration synthesis reactions
The reactions that assemble polysaccharides are examples of polymerization.
The most common are the plant starches, glycogen, and cellulose
61
What are proteins?
polymers of amino acids
vary hugely in terms of their composition and function.
examples - Structural, enzymatic, membrane transport, motile, regulatory, receptors, hormones, antibodies, storage, toxins.
62
What are polypeptides?
chains of amino acids.
Always has an -NH2 group at one end and a -COOH group at the other end.
63
proteins can be divided into _______ levels of structure, with each level imparting different characteristics and degrees of structural complexity to the molecule.
Four
64
What are the 4 levels of protein structure?
Primary
Secondary
Tertiary
Quarternary
65
What is the primary structure of a protein?
it is simply its complete amino acid sequence.
66
What is the secondary structure of a protein?
based on hydrogen bonds between the atoms of the backbone
The alpha helix
The beta sheet
67
What is the tertiary structure of a protein?
4 major interactions
1 - ionic bonds
2 - hydrogen bonds
3 - hydrophobic interactions
4 - disulfide bridges
the physical shape is flexible allowing them to undergo conformational changes
important for enzymes and proteins involved in cellular movement
68
What is the quarternary structure of a protein?
example = collagen
collagen consists of thee helical polypeptides that aggregate to form a triple-helix structure.
collagen is a major component in connective tissue
found exclusively in animals and is the most abundant protein in mammals.
69
What is a cofactor?
a nonprotein chemical compound that is bound to a protein and is required for the protein to function.
Also called a prosthetic group
organic cofactors are often called coenzymes
example - heme (hemoglobin)
