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What are essential to organisms?
Carbohydrates, lipids, proteins, and nucleic acids
Organic Molecules
Chemical compounds that contain carbon and usually hydrogen.
Macromolecule
A large molecule, made up of smaller building blocks or subunits.
Four types of macromolecules that are necessary for our cells...
-Carbohydrates -Lipids -Proteins -Nucleic Acids
Monomers
Relatively simple sets of building blocks, they are linked together by covalent bonds.
Polymers
A complex molecule formed by the linking together of similar building blocks—monomers—covalently bonded together.
Carbohydrates
The primary fuel for cellular activity and form much of the cell structure in all life forms.
Carbohydrates always contain...
-Carbon -Hydrogen -Oxygen
Glucose formula:
C6 H12 O6
Monosaccharides
The simplest carbohydrates and the building blocks of more complex carbohydrates.
Monosaccharides are also called...
Simple Sugars
Glucoses three fates:
It enters a cell and is used as fuel for cellular activity.
It is stored temporarily as glycogen.
Glucose circulating in your bloodstream can be converted into fat, a form of long-term energy storage.
Glycogen
A complex carbohydrate consisting of stored glucose molecules linked to form a large web, which breaks down to release glucose when it is needed for energy.
Primary function of carbohydrates in our cells
They are the primary fuel for cells
Why are carbohydrates the primary fuel for cells?
Because of their many carbon-hydrogen bonds. As those bonds are broken down and other, more stable bonds (primarily between carbon and oxygen) are formed, a great deal of energy is released that organisms can use.
What does water weight have to do with Glycogen?
The Glycogen stored in your muscles and liver are the first, most accessible molecules that can be broken down for energy in the absence of sufficient sugar in your bloodstream. And large amounts of water are bound to glycogen. As that glycogen is removed from your tissue, so is the water. This loss of water is responsible for much of the initial weight loss that occurs before your body resorts to using stored fat; the rate of weight loss then slows considerably
Complex carbohydrates
Disaccharides and polysaccharides
Disaccharide
Carbohydrates formed by the union of two simple sugars
Polysaccharide
Complex carbohydrates formed by the union of many simple sugars.
Example of Disaccharide and how its used:
Sucrose or table sugar - composed of the linked monosaccharides glucose and fructose. To use sucrose, the body first breaks the bond linking the glucose and the fructose. The individual monosaccharides are then broken down into their component atoms, and the energy that was stored in their chemical bonds is harvested and used.
Starch
A complex polysaccharide carbohydrate consisting of a large number of monosaccharides linked in line; in plants, the primary form of energy storage.
Two examples of polysaccharides and their functions
Starch - primary form of energy storage in plants Glycogen - stores glucose for later use in humans
Chitlin
A complex carbohydrate, indigestible by humans, that forms the rigid outer skeleton of most insects and crustaceans.
Cellulose
A complex carbohydrate, indigestible by humans, that serves as the structural material for a huge variety of plant structures. It is the single most prevalent organic compound on earth.
Why is cellulose an important part of the human diet even though humans cannot digest it?
The cellulose in our diet is known as "fiber." It is also appropriately called "roughage" because, as the cellulose of celery stalks, lettuce leaves, and the like passes through our digestive system, it scrapes the wall of the digestive tract. Its bulk and the scraping stimulate the more rapid passage of food and of unwanted, possibly harmful products of digestion through our intestines. In this way, fiber reduces the risk of colon cancer and other diseases
Lipids
One of the four types of biological macromolecules, insoluble in water and greasy to the touch.
Three types of lipids
-Fats -Phospholipids -Sterols
Why are lipids insoluble to water?
because they tend to have long chains consisting only of carbon and hydrogen atoms that are nonpolar
Hydrophobic
Repelled by water, as, for example, nonpolar molecules that tend to minimize contact with water.
Hydrophilic
Attracted to water, as, for example, polar molecules that readily form hydrogen bonds with water.
Calorie
The energy required to raise the temperature of 1 gram of water by 1 °C.
Fat
One of three types of lipids—made primarily from atoms of carbon, hydrogen, and oxygen—that functions in living organisms as a form of long-term energy storage.
Sterol
a group of organic molecules that includes cholesterol and many of the sex hormones that play regulatory roles in animals
Phospholipids
A group of lipids that are the major components of the plasma membrane. Phospholipids are structurally similar to fats, but contain a phosphorus atom and have two, not three, fatty acid chains.
Glycerol
A small molecule that forms the head region of a triglyceride fat molecule.
Fatty acids
A long hydrocarbon (a chain of carbon-hydrogen molecules), forms the tail region of triglyceride fat molecules.
Triglycerides
Fats having three fatty acids linked to the glycerol molecule
Saturated fat
Fats in which each carbon in the hydrocarbon chain forming the tail region of the molecule is bound to two hydrogen atoms; solid at room temperature
Unsaturated fat
Fats in which at least one carbon in the hydrocarbon chain forming the tail region of the molecule is bound to only one hydrogen atom; liquid at room temperature
Monounsaturated fatty acid hydrocarbon chain
has only one pair of carbon atoms in an unsaturated state—that is, it has only one double bond
Polyunsaturated fatty acid hydrocarbon chain
has more than one pair of carbons in an unsaturated state—there's more than one double bond
Trans fat
Unsaturated fats that have been partially hydrogenated. The added hydrogen atoms are in a trans orientation, which differs from the cis ("near") orientation of hydrogen atoms in the unsaturated fat
What does it mean when something is hydrogenated?
hydrogen atoms have been added to make the fat more saturated and to improve a food's taste, texture, and shelf life
Two sterols
-Cholesterol -Steroid Hormones
Cholesterol
One of the sterols, a group of lipids important in regulating growth and development; an important component of most cell membranes, helping the membrane maintain its flexibility.
Steroid Hormones
Regulate sexual development, maturation, and sex cell production (estrogen and testosterone)
Plaque
a mixture of cholesterol, fats, calcium, and clotting material
Some effects of estrogen
influences memory and mood, among other traits
One effect of testosterone
stimulate muscle growth
Waxes
Lipids similar in structure to fats but with only one long-chain fatty acid linked to the glycerol head of the molecule. Because the fatty acid chain is highly nonpolar, waxes are strongly hydrophobic.
Proteins
One of the four types of biological macromolecules, constructed of unique combinations of 20 amino acids that result in unique structures and chemical behavior. They are the chief building blocks of tissues in most organisms
Amino acids
One of 20 molecules built of an amino group, a carboxyl group, and a unique side chain. Proteins are constructed of combinations of these linked together.
Amino acids contain the same familiar atoms as carbohydrates and lipids—carbon, hydrogen, and oxygen—but they also contain...
nitrogen
Carboxyl group
A functional group characterized by a carbon atom double-bonded to one oxygen atom and single-bonded to another oxygen atom
Amino group
A nitrogen atom attached by single bonds to hydrogen atoms
Amino acids are made up of an...
-amino group -carboxyl group -side chain.
What makes one amino acid different from another?
The side chain
Complete protein
a protein that contains all the essential amino acids
Incomplete protein
a protein that is missing one or more of the essential amino acids
Proteins are formed by...
linking individual amino acids together with a peptide bond
Peptide bond
A bond in which the amino group of one amino acid is bonded to the carboxyl group of another
Dipeptide bond
Two amino acids joined together
Polypeptide
A chain of amino acids linked together to form all or part of a protein molecule.
Structures of proteins:
-Primary -Secondary -Tertiary -Quaternary
Primary structure
The sequence of amino acids in a polypeptide chain
Secondary structure
Hydrogen bonds between amino acids in the polypeptide chain can cause twisting or folding
Tertiary structure
The unique and complex three-dimensional shape of a protein formed by multiple twists of its secondary structure as amino acids come together to form hydrogen bonds or covalent sulfur-sulfur bonds.
Quaternary Structure
Two or more polypeptide chains bonded together in a single protein; an example is hemoglobin
Denaturation
The disruption of protein folding in which secondary and tertiary structures are lost, caused by exposure to extreme conditions in the environment such as heat or extreme pH
Enzyme
A protein that initiates and accelerates a chemical reaction in a living organism. They are found throughout the cell; they also take part in chemical reactions on the inside and outside surfaces of the plasma membrane
Can enzymes be used more than once?
Yes, When reactions are complete, enzymes are unchanged—they remain in their original form—and thus can be used again and again
Active site
The part of an enzyme to which reactants (or substrates) bind and undergo a chemical reaction
Substrate
The molecule on which an enzyme acts. The active site on the enzyme binds to this, initiating a chemical reaction
Activation energy
The minimum energy needed to initiate a chemical reaction (regardless of whether the reaction releases or consumes energy)
Relationship between enzymes and a reactions activation energy
Enzymes act as catalysts, initiating and speeding up the reaction, by lowering the activation energy
Factors that influence rate at which an enzyme catalyzes
-Enzyme and substrate concentration -Temperature -pH -Presence of inhibitors -Presence of activators
Enzyme and substrate concentration (enzyme activity)
The rate of a reaction typically increases with the addition of either more enzyme or more substrate, when such an addition causes a higher rate of collisions between enzyme and substrate molecules
Temperature (enzyme activity)
Reaction rates generally increase at higher temperatures, but only up to the optimal temperature for an enzyme.
pH (enzyme activity)
Reaction rates generally increase as pl nears the optimal level for an enzyme.
Presence of inhibitors or activators (enzyme activity)
Reaction rates decrease in the presence of inhibitors and increase in the presence of activators.
Competitive inhibitors
bind to the active site, blocking substrate molecules from the site and thus from taking part in the reaction
Noncompetitive inhibitors
do not compete for the active site, but rather bind to another part of the enzyme, altering its shape in a way that changes the structure of the active site, thus reducing or blocking its ability to bind with substrate
Activators
A chemical within a cell that binds to an enzyme, altering the enzyme's shape or structure in a way that causes the enzyme to catalyze a reaction
Why is it problematic if the shape of an enzyme is changed?
The active site or some other region of the protein molecule may change so that the enzyme will no longer function . Non Functioning enzymes are responsible for a large number of diseases and physiological problems
Nucleic acids
One of the four types of biological macromolecules, involved in information storage and transfer (DNA and RNA)
Deoxyribonucleic acid (DNA)
A nucleic acid that carries information, in the sequences of its nucleotide bases, about the production of particular proteins
Ribonucleic acid (RNA)
A nucleic acid that serves as an intermediary in the process of converting genetic information in DNA into protein, as well as other functions
Nucleotides
building blocks of nucleic acids
A nucleotide is made up of..
-Phosphate group -Sugar molecule -Nitrogen-containing molecule called a base
Base
One of the nitrogen-containing side-chain molecules attached to a sugar molecule in the sugar-phosphate backbone of DNA and RNA
Four types of bases a nucleotide can contain
-adenine -thymine -guanine -cytosine
Double helix
The spiraling ladder-like structure of DNA composed of two strands of nucleotides. The bases protruding from each strand like "half-rungs" meet in the center and bind to each other
Job of DNA in producing proteins
all of the DNA in a cell contains all of the instructions for every protein that humans must produce
Which bases always pair with each other?
In DNA, thymine always pairs with adenine, and cytosine always pairs with guanine. (A an T) (C and G)
Job of RNA in producing proteins
RNA serves the role of intermediary. First a copy of the DNA sequence is encoded in RNA, and then that RNA copy is used to direct the production of a polypeptide
Important differences between DNA and RNA nucleotides
The sugar portion of the nucleotide contains an extra atom of oxygen.
While RNA has the bases A, G, and C, it does not have thymine (T); instead, it has a similar base called uracil (U).
3.RNA is single-stranded. Its bases do not bind with bases in another RNA strand to form the ladder-like structure of DNA.
Cell
The most basic unit of any organism, the smallest unit of life that can function independently and perform all the necessary functions of life.
The term cell was first used in the mid-1600s by...
Robert Hooke
Cell theory
A unifying and universally accepted theory in biology
Two major principles of cell theory:
All living organisms are made up of one or more cells
2.All cells arise from other, preexisting living cells
Note
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