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97 terms

Ch 2 Test

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anaerobic respiration
produces lactic acid
lipid respiration
produces fatty acids and ketones
hemoglobin
transports oxygen to cells of the body
weak bases
absorb H+
weak acids
donate H+
salts
examples of electrolytes, inorganic compounds whose ions can conduct electrical current in solution
titrate
the gradual addition of a solution of known strength and measuring the volume necessary to convert the constituent to another form
Bicarbonate Buffer System
H+ + HCO3- --> H2CO3 --> CO2 + H2O
strong acid + weak base --> weak acid -->
both are part of equilibrium system
Too much OH- in the blood? bicarb
disfunction of urinary system
OH- + H2CO3 --> HCO3- + H2O
strong base + weak acid --> weak base
HCO3 is excreted by the kidneys
prevent pH changes caused by organic (metabolic) acids
Protein Buffer System
not as much of an equilibrium system
accounts for 75% of all chemical buffering ability of body fluids
lower pH? protein
-COOH --> -COO- + H+
carboxyl group acts like an acid when needed
protein donor
raise pH? protein
-NH2 + H+ --> -NH3+
amino group acts like a base when needed
protein acceptor
maintain acid-base balance
For homeostasis to be preserved, H+ must be REMOVED from body fluids. The RESPIRATORY SYSTEM and KIDNEYS support the buffer systems.
involved balancing H+ loss/gain
Phosphate Buffer System
H2PO4- --> H+ + HPO4-2
in the ECF
phosphate buffer system plays a supporting role because there are more HCO3-
in the ICF
phosphate buffer system is very important where there is a high concentration of phosphate ions
pH < 7.35
acidosis (more common)
pH > 7.45
alkalosis
nervous system and cardiovascular system
particularly sensitive to pH fluctuations
partial pressure of CO2 and pH
inversely related
Protein buffer system
regulates pH in ECF and ICF
Bicarbonate buffer system
important, in the ECF if H+ are removed, they'll be replaced through combining of water with CO2
If H+ are added, most will be removed by forming CO2 and H2O
Bicarbonate buffer system
can cope with large amounts of acid because body fluids contain many bicarb ions, aka bicarb reserve
Phosphate buffer system
consists of an anion, H2PO4-
concentration of bicarb ions is way more than that of phosphate ions
important in buffering pH of ICF--> where phosphate ion concentration is high
respiratory and renal mechanisms
support buffer systems by 1. secreting/absorbing H+; 2. controlling excretion of acids and bases; 3. generating additional buffers
the combo of buffer systems and these respiratory and renal mechanisms maintain body pH within narrow limits
4 major classs of organic compounds in human body
carbs --> sugars, starches
lipids --> fats, oils, waxes
proteins --> hemoglobin, keratin
nucleic acids --> DNA and RNA
carbohydrates
an organic molecule that contains carbon, hydrogen, and oxygen in a ratio near 1:2:1
most important energy source
glucose is most important metabolic fuel in body
all must be disassembled through hydrolysis before used as energy
excess sugar is stored as fat
3 major types of carbs
monosaccharides, disaccharides, polysaccharides
monosaccharides
3-7 carbon atoms; energy source; manufactured in the body and obtained from food, found in body fluids
ex: glucose, fructose, galactose (all 3 are structural isomers)
disaccharides
2 monosaccharides; energy source; all must be broken down to monosaccharides before absorption
ex: sucrose --> table sugar (glucose and fructose)
lactose --> present in milk (glucose and galactose)
maltose --> milk sugar (glucose and glucose) in germ. wheat
polysaccharides
storage of glucose molecules
ex: glycogen --> in animal cells
other starches and cellulose are in plants
glycogen
a polysaccharide composed of interconnected glucose molecules
stored in muscle cells and liver cells
aka animal starch
4 major types of lipids
fatty acids, fats, steroids, phospholipids
fatty acids
end with carboxyl group; energy source; absorbed from food or synthesized in cells, transported in the blood for use in many tissues
ex: lauric acid, butter, fatty meat, vegetable oils
fats
energy source and storage; insulation and physical protection; stored in fat deposits, broken down to fatty acids and glycerol
ex: oils, monosaccharides, diglycerides, triglycerides (most common) (3 fatty acids bonded to a 3 C glycerol)
steroids
large lipid molecules made of 4 connected C rings, structural component of cell membranes, hormones, digestive secretions in bile --> carbon ring framework
ex: cholesterol ("parent steroid") like estrogen and testosterone
phospholipids
glycerol and 2 fatty acids linked to a nonlipid group, structural component of cell membranes, composed of fatty acids and nonlipid molecules
ex: in cell membranes, lecithin
structure of proteins
each amino acid consists of a central carbon atom bonded to a hydrogen atom, an amino group, and a variable R group or side chain; the structure is established by the sequence of amino acids; long chains; 20 different amino acids are building blocks of proteins; shape determines function; large protein = over 100,000 amino acids; typical protein: 1000 amino acids joined by peptide bonds; changing one amino acid chain of 10,000 can cause protein not to work
characteristics of proteins
400,000 different kinds; all contain carbon, hydrogen, oxygen, and nitrogen; long chains of organic molecules called amino acids; 7 categories of protein function; transport through blood; metabolic regulation by enzymes; buffering; cell support structure; movement and muscle contractions; coordination, communication, control by hormones; defense anti-bodies, clotting proteins (blood)
characteristics of enzymes
work best at optimal temp and pH; catalyze reactions that sustain life; substrates must bind to the active site before an enzyme can function as a catalyst; work quickly; they catalyze only 1 type of reaction; substrates are reactants; aren't used up; most important protein
nucleic acids
large organic molecules composed of carbon, hydrogen, oxygen, nitrogen, and phosphorus; store and process info at the molecular level inside cells; ex: DNA and RNA; made of nucleotides which are made of a sugar, phosphate group, and nitrogenous base
DNA
double strands; deoxyribose; adenine, guanine, cytosine, thymine; longer; stores info controlling protein synthesis
RNA
single strand; ribose; adenine, guanine, cytosine, uracil; short; protein synthesis
ATP
breakdown of food; 1 more phosphate group (3); forms ADP; high chem energy
ADP
low energy molecule; 2 phosphate groups attached
If the pH of blood needs to increase, which group acts like a base?
amino group
NH2
If the pH of the blood needs to decrease, which group acts like an acid?
carboxyl group
-COOH-
If there is too much OH- in the blood, what compound reacts with OH- to produce a weak base?
H2CO3 (carbonic acid)
If there is too much H+ in the blood, which compound will react with H+ to produce a weak acid?
HCO3- (bicarbonate ion)
What compound acts as a weak base?
HCO3-
What compound acts as a weak acid?
H2CO3
R group
what is different for every amino acid
enzymes
substrate specific
are proteins
all aid in digestion
Buffer lab
It worked because when adding strong base, NAOH, there wasn't a fast change in pH. It was a gradual change because the buffer (vinegar) was trying to resist a pH change. The OH- was accepting a proton from buffer, vinegar.
OH- + H+ --> H2O
Buffer lab equation
vinegar + sodium hydroxide --> sodium acetate + H2O
weak acid (buffer) + strong base --> weak base
enzymes belong to a class of substances called _______, which accelerate chemical reactions without themselves being permanently changed
catalysts
special molecules called enzymes found in cells ______
speed up reactions that support life, produce energy to start a chemical energy, release activation energy for a reaction to proceed
When an enzyme promotes a chemical reaction by lowering the activation energy, it only affects the ____
rate of reaction
exergonic reactions, which are common in the body, are responsible for _____
generating the heat that maintains your body temperature
the activation energy requirement of a reaction is much lower in the presence of _______
an appropriate enzyme
organic compounds differ from inorganic compounds in that organic compounds are primarily composed of ______
carbon and hydrogen atoms and are much larger and more complex
the most important inorganic compound found in large quantity in the body ____
water
compounds that contain the elements carbon, hydrogen, and usually oxygen are ______ compounds
organic
acids, bases, and salts are examples of _____ compounds
inorganic
water
excellent solvent, high heat capacity, essential reactant in the chemical reactions of living systems
during ionization, water molecules disrupt the ionic bonds of a solute and a mixture of ions is produced. these ions are called ____
electrolytes
most chemical reactions in the body take place in ____
solution
a homogenous mixture containing a solvent and a solute is called a _____
solution
soluble inorganic compounds whose ions will conduct an electric current in a solution are ___
electrolytes
pH is a measure of the concentration of ____ in solution
hydrogen ions
a solution with the pH below 7 is ___
acidic
compounds that stabilize pH by either removing or replacing hydrogen ions are ____
buffers
least acidic
urine with ph 6 isn't as acidic as lemon juice with ph of 2
pH greater than 7 ____
Alkaline, basic
To maintain homeostasis in the body, the normal pH range of the blood must remain at ___
7.35 to 7.45
A solution with a pH of 7 that contains equal number of hydrogen ions and hydroxide ions is called ____
neutral
A solute that dissociates to release hydrogen ions and causes a decrease in pH is ____
an acid
A solute that removes hydrogen ions from a solution is ____
a base
in the body, inorganic compounds _____
serve as buffers
inorganic ions are important in the functions of ____
blood clotting, muscle contractions, nerve impulse conduction
a weak acid that serves at an effective buffer in the body is ___
carbonic acid
a salt may be best described as ___
inorganic molecule created by the reaction of an acid and a base
carbs are most important to the body because they serve as primary sources of ____
energy
most important metabolic fuel molecule in the body ___
glucose
the polysaccharide formed by stored glucose in the liver and muscle is ___
glycogen
most of the fat found in the human body is in the form of ___
triglycerides
butter, fatty meat, and ice cream are examples of sources of fatty acids that are said to be ____
saturated
a steroid molecule is an example of ____
lipid
the building blocks of proteins consist of chains of small molecules called ___
amino acids
proteins differ from carbohydrates in that they ___
always contain nitrogen
each amino acid differs from others in the ___
nature of the R group
special proteins that are involved in metabolic regulation are called ___
enzymes
the molecules that store and process info at the molecular level are the ___
nucleic acids
three basic components of a single nucleotide of a nucleic acid are ____
sugar, phosphate group, nitrogen base
in DNA and RNA, a nucleotide containing the nitrogen base cytosine would only base-pair with ___
guanine
the most important high-energy compound in cells is ___
ATP
why do human bodies need buffers?
When someone exercises a lot, lactic acid starts to build up in the blood stream. This causes the pH to lower. If the pH ever gets below 6.8, the effects can be deadly. Buffers help to neutralize the lactic acid and keep the pH at a healthy level.