water makes up approx what percent of:
1) human body
2) human blood
50-60% of human body
92% of human blood
define solubility
the abilility of one substance to disolve in another
Define Induced Fit Hypothesis:
enzymes change shape to accommodate the shape of specific reactants
Electrolyte:
any substance containing free ions
Heterogeneous mixture:
do not have a uniform composition throughout themixture and can be separated physically
Homogeneous mixture:
same composition throughout with uniform appearance
Acid:
a proton donor or any substance that releases hydrogen ions
Base:
a proton acceptor or any substance that binds to oraccepts hydrogen ions
Salt:
a compound consisting of a cation other than a hydrogen ion and an anionother than a hydroxide ion. Example: NaCl
Buffer:
an ionic compound that resists changes in its pH
When H+ added, buffer removes it
When H+ removed, buffer replaces it
Acid= H+ __ OH-
>
Base = H+ __ OH-
<
Neutral = H+ __ OH-
=
Oxygen (O2):
required in the final step in theseries of reactions used to extract energy from food.
Carbon dioxide (CO2):
produced during the catabolism of organic compounds.
Metabolic waste product.
Combines with water in plasma and
forms H+ thus affecting acid/base balance
Inorganic Chemistry:
generally, substances that do not contain carbon
Water, oxygen, calcium phosphate, metalionsExceptions: CO, CO2, and HCO3-
Organic Chemistry:
study of carbon-containing substances
Carbohydrates:
composed of carbon, hydrogen, oxygen.
Divided into monosaccharides, disaccharides, polysaccharides
Energy sources and structure
Lipids:
composed mostly of carbon, hydrogen,oxygen.
Relatively insoluble in water.
Functions: protection, insulation,component of cell membranes, energy source
Proteins:
composed of carbon, hydrogen, oxygen, nitrogen, sometimes iodine.
Functions: regulate processes, aid
transport, protection, muscle contraction, structure, energy
Nucleic Acids:
composed of carbon, hydrogen, oxygen, nitrogen, phosphorus.
Examples: DNA, RNA, ATP(nucleotide)
The building blocks of carbohydrates are?
Monosaccharides
Disaccharides:
Two simple sugars bound together by
dehydration synthesis
Examples: sucrose, lactose, maltose
Polysaccharides
Long chains of many monosaccharides.
Glycogen formed by animals.
Starch and cellulose formed by plants
Starch in food is used as a
source of monosaccharides
Cellulose in food acts as fiber
(bulk) in the diet
Lipids:
Fats
Ingested and broken down by hydrolysis
Triglycerides: composed of glycerol and three
fatty acids.
Functions: protection, insulation, energy
source
Saturated fats –
contains all single bonds inthe carbon chain, which produces a more rigid structure. Solid at room temperature
Unsaturated fats–
contains one (mono) or more(poly) double bonds in the carbon chain, which produces a more relaxedstructure. Liquid at room temperature.
Better because they do not stickto the inside of blood vessels.
Trans fats –
unsaturated fats that are artificially altered to be more saturated.
Are the highest CV risk fat
Lipids:
Phospholipids
Polar (hydrophilic) at one end; nonpolar
(hydrophobic) at the other.
For example, water is a polar
molecule and oil is a non-polar molecule. A polar and non-polar combination
will not form a solution; therefore, oil and water won't form a solution.
Function: important structural component of cell
membranes
Lipids:
Steroids
Cholesterol, bile salts, estrogen,
testosterone.
Carbon atoms arranged in four
rings
Functions: physiological regulators and
component of cell membranes
true or false
Cholesterol cannot dissolve in the blood. It has to be transported to and from the cells by
carriers called lipoproteins
true
Low-density
lipoprotein, or LDL
is known as “bad”
cholesterol.
Composed mainly of cholesterol and have
very little protein.
Primarily responsible for depositing
cholesterol within arteries.
High levels of LDLs are associated with
an increased risk for coronary heart disease.
High-density lipoprotein =
HDL, is known as “good” cholesterol. Composed mainly of proteins, with onlysmall amounts of cholesterol.Help remove cholesterol from artery wallsand transport it to the liver for elimination from the body. Higher HDL levels actually protectagainst coronary heart disease
what is the building blocks of protein?
amino acids
Peptide bonds:
covalent bonds formed between aminoacids during protein synthesis
dipeptide =
a molecule consisting of two amino acids joined by a single peptide bond.
Polypeptide:
A peptide consisting of 2 or more aminoacids
why are essential amino acids essential?
because the body does not synthesize them, making it essential to include them in one's diet in order to
obtain them.
Nonessential amino acids
The amino acids that your body can produce on its own.
Structural proteins
Proteins with the primary purpose of producing the essential structural components of the cell.
Provide stiffness and rigidity to otherwise-fluid biological components
Functional proteins:
Have the ability to carry out metabolic processes.
Example: enzymes
what is the building blocks of DNA and RNA
nucleotides
Nucleotides =
Composed of a five-carbon sugar, a nitrogenous base, and a phosphate
Include the nucleic acids (DNAand RNA) and ATP
what does DNA stand for
Deoxyribonucleic acid
In humans, DNA is located primarily inside...
the cell nucleus, but some DNA is also located in mitochondria
The main role of DNA is?
the long-term storage of information
what are the 4 nitrogenous bases of DNA and which bond with which?
Adenine (A) binds with thymine (T), Cystosine (C) binds with guanine (G)
what does RNA stand for
RNA: Ribonucleic acid
in stead of thymine RNA has what as its 4th nitrogenous base
(U) Uracil
Adenosine
Triphosphate (ATP)
Nucleotide
Energy currency of the body
Provides energy for other chemical reactions such as anabolism or drive cell processes such as muscle contraction
All energy-requiring chemical reactions stop when there is inadequate ATP
Basic Structure of the Cell (3)
Plasma membrane
Cytoplasm containing organelles
Nucleus
what are the Functions of the Cell
Cell metabolism and energy use
Synthesis of molecules
Communication. Cells produce and receive electrical
and chemical signals
Reproduction and Inheritance. Each cell contains DNA. Some cells are
specialized to gametes for exchange during sexual intercourse
Plasma Membrane
Separation of intracellular vs. extracellular materials
Production of charge difference (membrane potential) across the membrane by regulation of intracellular and extracellular ion concentrations
Outside of membrane positively charged compared to inside because of gathering ions along outside and inside
Membrane Lipids
Phospholipids and cholesterol predominate
Phospholipids: bilayer. Polar heads facing water in the interior and exterior of the cell (hydrophilic); nonpolar tails facing each other on the interior of the membrane (hydrophobic)
Cholesterol: interspersed among phospholipids. Amount determines fluid nature of the membrane
Fluid nature provides/allows Distribution of molecules within the membrane
Phospholipids automatically reassembled if membrane is damaged
Membranes can fuse with each other
Marker Molecules:
Glycoproteins and Glycolipids
Allow cells to identify one another or other molecules
Immunity
Recognition of oocyte by sperm cell
Intercellular communication
2 types of Channel Proteins
gated and non-gated
non gated ion channel
always open
Responsible for the permeability of the plasma membrane to ions when the plasma membrane is at rest
Gated ion channels
can be opened or closed by certain stimuli
Ligand gated ion channel:
open in response to small molecules that bind to proteins or glycoproteins
Voltage-gated ion channel:
open when there is a change in electrical charge across the plasma membrane
Carrier Proteins
Also called transporters
Integral proteins move ions from one side of membrane to the other
Have specific binding sites
Protein changes shape to transport ions or molecules
Resumes original shape after transport
what are the three forms of carrier proteins?
Uniporters – moves one particle
Symporters – move two particles in the same direction at the same time
Antiporters – move two particles in opposite directions at the same time
Receptor Proteins
Proteins or glycoproteins in membranes with an exposed receptor site
Can attach to specific chemical signal molecules and act as an intercellular communication system
Ligand can attach only to cells with that specific receptor
Receptors Linked to Channel Proteins
Receptor molecules linked to channel proteins
Attachment of receptor-specific chemical signals (e.g., acetylcholine) to receptors causes change in shape of channel protein, Channel opens or closes
Changes permeability of cell to some substances
Enzymes
some act to catalyze reactions at outer/inner surface of plasma membrane.
Surface cells of small intestine produce enzymes that digest dipeptides
5 types of Movement through the Plasma Membrane
Diffusion
Osmosis
Mediated Transport
Facilitated diffusion
Active transport
Diffusion
Movement of solutes from an area of higher concentration to lower concentration in solution
Concentration gradient: difference between two points
Osmosis
Diffusion of water (solvent) across a selectively permeable membrane.
Water moves from an area of low concentration of solute to an area of high concentration of solute
Isotonic:
solutions with the same concentrations of solute particles
Solution with a greater concentration of solute is
hypertonic
Solution with a lesser concentration of solute is
hypotonic
shrinkage or swelling - isotonic?
cell neither shrinks nor swells
shrinkage or swelling - hypotonic
cell swells (lysis)
shrinkage or swelling - hypertonic
cell shrinks (crenation)
Mediated Transport
Involve carrier proteins or channels in
the cell membrane
Specificity for a single type of molecule
Competition among molecules of similar shape
Saturation: rate of transport limited to number of available carrier proteins
Mediated Transport – Facilitated Diffusion
Facilitated diffusion: carrier- or channel-mediated. Passive.
Move large, water soluble molecules or electrically charged molecules across the plasma membrane.
Amino acids and glucose in, manufactured proteins out.
Mediated Transport – Active Transport
ATP-Powered Transport
Requires ATP. The use of energy allows the cell to accumulate substances
Rate of transport depends on concentration of substrate and on concentration of ATP
Example: Na+/K+ exchange pump that create electrical potentials across membranes
Endocytosis
Internalization of substances by formation of a vesicle