bio test 1 Flashcards
(106 cards)
1
Q
what is water made up of
A
2 hydrogen atoms and 1 oxygen atom
2
Q
what kind of bond holds water together
A
covalent bond
3
Q
how does a covalent bond form
A
it forms between atoms when each atom shares electrons
4
Q
how are electrons shared in a water molecule
A
one electron from oxygen atom and one from hydrogen atom is shared to make a covalent bond; the electron pair is thus shared by both oxygen and hydrogen. However, the sharing is not equal. Oxygen atom is more electronegative. It attracts electrons towards itself more than hydrogen.
5
Q
what are electrons
A
negatively charged ‘particles’ ( 1 electron = 1 negative charge)
6
Q
is oxygen slightly negative or positive
A
slightly negative (delta negative)
7
Q
is hydrogen slightly negative or positive
A
slightly positive (delta positive)
8
Q
what does the slightly negative oxygen and slightly positive hydrogen result in
A
a molecule with slightly negative and positive poles (ends)
9
Q
is a water molecule polar
A
yuh
10
Q
dissolving and water
A
water can dissolve many things to a great extent and others to a lesser one or slightly lesser one. for this reason, water is known as a universal solvent.
11
Q
does water dissolve other polar or ionic substances to a large extent
A
yuh
12
Q
the slightly negative (delta negative ) ___ is attracted to the slightly positive (delta positive) ___ between neighbouring water molecules
A
oxygen, hydrogen
13
Q
due to an attraction between hydrogen of one water molecule and oxygen of another, the water molecules are held together by a weak bond called ___
A
hydrogen bond/hydrogen bonding
14
Q
properties of water:
A
1) Water molecules are cohesive and adhesive which makes it a lubricant
2) Water molecules are polar which makes it a good solvent
3) Water has a high heat capacity and high heat of vaporization which makes it a good temperature regulator
15
Q
cohesive
A
refers to water molecules being able to stick/stay together
16
Q
adhesive
A
refers to water molecules being able to stick to other surfaces
17
Q
examples of water as a lubricant in our bodies:
A
1) lubricant in bone joints
2) lubricant in mucus and saliva
3) lubricant in digestive juices
4) lubricant in semen
18
Q
does water have a high heat capacity and high heat of vaporization?
A
yuh
19
Q
water is able to retain large amounts of ___
A
heat
20
Q
does water have a high heat of vaporization?
A
yes. water is able to absorb large amounts of heat before it begins to evaporate
21
Q
2 examples of water as a temperature regulator:
A
1) Normal human body temperature = 37 degrees Celsius; biochemical reactions in our body occur best at 37 degrees Celsius. when the body temp falls below normal, water retains. when the body temp rises above normal, water releases excess heat and the normal temp is maintained.
2) When it gets cold, shivering is another mechanism through which water in blood is able to retain heat to maintain normal body temperature.
22
Q
acids and example of one in our bodies
A
compounds which produce hydrogen ions when dissolved in water.
ex: HCl produced in stomach
23
Q
bases and example of one in our bodies
A
compounds which produce hydroxide ions when dissolved in water.
ex: HCO3- (bicarbonate ion). NaHCO3 is a salt which dissociates into sodium ion and bicarbonate ion.
24
Q
pH
A
a measure of how many hydrogen ions there are in a given solution
25
when pH = 7, the solution is ___
neutral. the solution has equal amounts of hydrogen and hydroxide ions
26
when pH is greater than 7, the solution is ___
alkaline/basic. the solution has less hydrogen ions compared to OH- ions
27
when pH is less than 7, the solution is ___
acidic. the solution has more hydrogen ions compared to OH- ions
28
human blood has a slightly basic pH of ___
7.34 to 7.40
29
do pH and hydrogen vary opposite to each other?
yes. when the concentration of hydrogen ions increases the pH decreases so it becomes more acidic.
30
low pH indicates ____ while high pH indicates ___
an acidic solution, a basic solution
31
when the hydrogen concentration is up, the pH is down and ___
when the hydrogen concentration is down, the ph is up and ___
the solution becomes more acidic
the solution becomes more basic/alkaline.
32
significance of pH and 3 examples
biochemical reactions in our bodies occur best at optimum pH; the wrong pH will result in no reaction or process.
ex: 1) Saliva in mouth contains a starch digestive enzyme,
‘salivary amylase’, works best at 7 pH
2) Stomach produces a protein digestive enzyme, ‘pepsin’, works best at 2-3 pH.
3)Pancreas and small intestine produce digestive enzymes, work best at 8-9 pH.
33
explain biological buffers
Each biochemical has its own optimum pH. Buffers are the substances which help maintain pH in a narrow range.
34
explain 3 examples of biological buffers in the body:
1) Hemoglobin (Hb): pigment in our red blood cells (RBC) maintains constant blood pH of 7.34-7.40. pH of blood drops below normal= excessive hydrogen ions. Blood buffer removes extra hydrogen ions by binding with them. blood pH rises above normal= not enough hydrogen ions. Hemoglobin releases H+ ions as needed.
Hb + H+ ↔HHb 2) Bicarbonate ions, HCO3- , and the breathing system also helps maintain constant pH. HCO3- + H+ ↔ H2CO3 3) Bone buffer system helps maintain pH
35
monomer
mono = 1
| refers to the building blocks/unit molecules
36
polymer
poly = many
| refers to macromolecules/larger molecules made by putting together monomers/unit molecules/building blocks
37
examples of monomers and the polymers they can turn into
- glucose/monosaccharides => starch, glycogen, cellulose (polysaccharides)
- amino acids => proteins/polypeptides
- nucleotides => nucleic acids
- 3 fatty acids + glycerol => triglycerides/neutral fat/lipid
- 2 fatty acids + phosphate + glycerol => phospholipids
38
dehydration/condensation synthesis
- refers to the making of a polymer from its monomers
- the "OH" of one monomer and the "H" of another monomer join to make a molecule of water
- when water is removed, the 2 monomers join to make a polymer
39
2 examples of dehydration synthesis
- protein synthesis (recognize the diagram)
- excess blood glucose (monomer) is converted into glycogen (polymer) in the liver with the help of the hormone insulin produced by the pancreas. glycogen is stored in the liver.
40
hydrolysis
- refers to breaking apart a polymer into its monomers with the help of water
- water is added in the process of hydrolysis
41
example of hydrolysis
- our digestive system breaks down the polymers we consume into their monomers with the help of digestive enzymes
- the monomers are small enough to enter the blood. di or poly cannot enter the blood because they are too big to enter blood capillaries
42
many monomers produced by the digestive system first enter the ___ where they are reprocessed and used as needed
liver
43
some polymers that we consume
- starch (bread, pasta, potato)
| - proteins (meat, egg white)
44
some monomers produced by digestive system
- monosaccharides/glucose, fructose, etc
| - amino acids
45
anabolism
synthesis biochemical reactions
46
catabolism
degradation biochemical reactions
47
metabolism
sum of all biochemical reactions in the body = anabolism + catabolism
48
4 classes of organic polymers
carbohydrates, lipids, nucleic acids and proteins
49
polymer that forms enzymes
proteins
50
polymers that may form hormones
proteins and lipids (steroids)
51
carbohydrates
- all contain carbon, hydrogen and oxygen
- three main kinds are monosaccharides, disaccharides and polysaccharides
- used for quick and short-term energy storage
52
monosaccharides
- mono = 1. saccharide = sugar. monosaccharides are monomers.
- simplest formula of monosaccharide is CH2O
- only monosaccharides are small enough to enter blood capillaries
- main function: serve as immediate source of energy for cell
53
examples of monosaccharides
- glucose
- fructose
- galactose
54
disaccharides
- made by joining 2 of the same type or different types of monosaccharides
- not small enough to enter blood. they must be broken down into monosaccharides by digestive system to enter the blood
- main function is to provide monosaccharides
55
examples of disaccharides
- maltose, which is made when 2 glucose molecules join
- sucrose (table sugar) which is made when glucose and fructose join
- lactose (milk sugar) which is made when galactose and glucose join
56
if a biological molecule's name ends in "ose"...
it's most likely a simple sugar like glucose
57
3 types of polysaccharides
- starch
- glycogen
- cellulose
58
starch
- branched structure
- main function is to provide monosaccharides
- produced by plants by photosynthesis, consumed by humans/animals
59
glycogen
- heavily branched structure
- made in the liver
- excess blood glucose/ sugar is converted into glycogen by the hormone insulin which is produced by the pancreas
- glycogen is stored in the liver and is slowly converted into glucose between meals as needed by the action of the hormone glucagon which is also produced by the pancreas
60
cellulose
- unbranched structure
- found in plant cell walls
- joined by a slightly different type of linkage, and we are unable to digest foods with this kind of linkage
- humans cannot digest cellulose/fibre as we do not have the enzyme that is needed to digest cellulose
- in the distant past, humans were able to digest cellulose as the needed enzyme was produced by our vermiform appendix. now, the appendix is considered a vestigial organ
61
what can glycerol turn into
a triglyceride
62
monosaccharides, disaccharides and polysaccharides may be compared by the number of _____ they contain
monosaccharide (or glucose) molecules
63
structure of proteins
- proteins are polymers/biopolymers
| - the monomers/ building blocks of proteins are amino acids
64
general structure of amino acid
- NH2 on left (amino group)
- Carbon in middle, Hydrogen above carbon
- R-group below carbon (side chain)
- COOH on right (carboxyl group). OH to right of C, O on top of C with double bond.
65
describe amino acids
- there are 20 different amino acids
- all have an amino group and a carboxyl group
- they differ from one another in their R-group and the number of amino acids in the sequence
66
what kind of bond joins amino acids to each other?
peptide bonds (type of covalent bond)
67
what is the backbone of a polypeptide composed of?
- NCC NCC NCC NCC...
68
primary level/structure of protein
- linear
- not a functional protein, just a polypeptide
- main type of bond / bonding is peptide bond
69
difference between polypeptide and protein
- all proteins are polypeptides, but not all polypeptides are proteins. a polypeptide is merely a single chain of amino acids
- proteins are functional units with specific functions. sometimes the formed polypeptides may not be functional, so we don't call them proteins
70
secondary structure of protein
- alpha helix or beta pleated
| - main typing of bond is hydrogen bonding between peptide bonds
71
tertiary structure of protein
- many proteins become functional at this stage (ex/ the muscle protein myosin)
- 3-D structure
- hydrophobic portions on inside, hydrophilic regions on outside
- main type of bond is ionic, covalent bonds between R-groups is disulphide bonds between 2 amino acids
72
quaternary structure of protein and example
- results when several polypeptides join together to make a team of one functional protein
- in red blood pigment, hemoglobin (Hb), 4 polypeptides join to make one quaternary protein
73
talk about protein shape
- proteins have definite shape
| - a protein's shape is important for the function(s) it performs
74
denaturation
refers to the destruction of a protein's shape/structure by disturbing normal bonding between R-groups, rendering the protein non-functional
75
3 main factors that cause denaturation
- extreme heat. in the human body, temperatures above 37 degrees Celsius can denature proteins
- wrong/unsuitable pH
- presence of heavy metals such as lead and mercury (long term effects)
76
structural protein and examples
- make up our structures
| - keratin makes hair, collagen makes tendons, muscle proteins, bone proteins, etc
77
enzymes and examples
- almost all are proteins which speed up biochemical reactions in cells (like digestive enzymes such as amylase, lipase, etc)
78
if you have a name ending in "ase," it's most likely a ___
enzyme (a type of protein!)
79
hormones and example
- chemical messengers
| - some hormones such as insulin are proteins
80
list uses/ functions of protein
- structural
- enzymes
- hormones
- transport
- storage
- contractile
- antibodies
81
proteins as transportation and example
- transport things in our body
| - hemoglobin (Hb) transports oxygen in blood
82
protein as storage and example
- albumin is produced in liver, it stores substances
83
contractile proteins
- muscles are made up of proteins; contractile proteins contract and relax to cause movement
84
proteins as antibodies
- antibodies or immunoglobulin help defend against pathogens such as viruses and bacteria - they identify and destroy pathogens
85
lipids
organic molecules which are insoluble in water (lard, butter, oil)
86
emulsification
- process of causing fats or oils to disperse into tiny droplets in water
- fats are emulsified by bile which is produced by the liver
- this increases the surface area that the enzyme lipase can work on to break fat into fatty acids and glycerol
- when people have their gall bladders (where bile is stored) removed, they are unable to emulsify and must eat fewer fatty foods
87
types of lipids
- neutral fats (triglycerides)
- phospholipids
- steroids and cholesterol
- oils and waxes
88
neutral fats
- 3 fatty acids + glycerol
- the enzyme lipase produced by the pancreas breaks down these fats into fatty acids and glycerol. these are absorbed into the lacteals in the Villi of the small intestine
- provides long term energy storage, cushioning around major organs, and insulation
89
fatty/carboxylic acids
long chain of carbon atoms with hydrogen attached, chain ends with carboxyl acid or COOH group
90
saturated fats
- no double bonds between carbons of the backbone chain
| - saturated with all the hydrogens it can hold
91
unsaturated fats
- have fatty acids which are short of hydrogens and have double bonds between the carbons
- can be very long chains
92
glycerol
recognized by 3 vertical carbons
93
phospholipids
- glycerol + 2 fatty acids (tails) + phosphate group (head)
- each has polar (hydrophilic head) region. it is water attracting and soluble in water
- each has nonpolar (hydrophobic tails) region. it's water repelling and insoluble in water
- important in formation of cell membranes. in water, they form a phospholipid bilayer as the polar heads are attracted to water. tails orient themselves away from the water
94
phospholipid bilayer
- cell membrane
| - these molecules have a charge at one end which make selective barrier properties of the membrane
95
steroids and cholesterol
- general structure consists of 4 joining carbon rings
- cholesterol and steroids differ in their tails
- cholesterol is used in cell membranes and can be converted to steroids
- steroids can be hormones like aldosterone, testosterone and estrogen (hormones can be either proteins or lipids)
96
monomers of nucleic acids are ___
nucleotides
97
RNA (ribonucleic acid) nucleotides contain
- phosphate (P)
- sugar (S) = ribose sugar
One of the following nitrogenous bases:
- A = adenine
- U = uracil
- C = cytosine
- G = guanine
98
DNA (deoxyribose nucleic acid) nucleotides contain:
- Phosphate (P)
- sugar (S) deoxyribose sugar
ONE of the following nitrogenous bases:
- A = adenine
- T = thymine
- C = cytosine
- G = guanine
99
ATP (adenosine triphosphate)
- referred to as the energy currency of the cell
- cell uses ATP whenever/wherever it needs energy.
- Most ATP is produced in the mitochondria by cellular respiration (36-38 ATP molecules produced)
- energy is released from ATP when the high energy (wavy) phosphate bond breaks: ATP => ADP (adenosine diphosphate) + energy
- C6H12O6 + 6O2 => 38 ATP +6CO2 +6H2O
100
carbohydrates are macromolecules composed of ___ monomers
monosaccharide
101
Which type of organic macromolecule is used primarily for energy and structure?
carbohydrates
102
Which type of lipid has four fused carbon rings?
cholesterol
103
___ bonding gives water its unique properties (minus water being a universal solvent)
hydrogen
104
a ___ bond joins a dipeptide bond of amino acids
peptide
105
when an atom donates an electron, it becomes ___ charged
| when an atom receives an electron, it becomes ___ charged
positively, negatively
106
organic molecules
- always contain carbon and hydrogen
