Bio I - 4 Flashcards
What are living organisms mostly consisting of?
Carbon based compounds
What ability makes carbon unparalleled…
It’s ability to form large complex and varied molecules
What is composed of carbon?
Proteins, DNA, carbohydrates, and other molecules
What is organic chemistry?
It is the study of compounds that contain carbon
How many valence electrons does carbon have? And how many covalent bonds can carbon therefore form?
4
4
What are functional groups?
They are the components of organic molecules that are most commonly involved in chemical reactions
What are some common functional groups that are most important in the chemistry of life?
Hydroxyl group, carboxyl group, amino group, sulfhydryl group, phosphate group
What is ATP?
An important organic phosphate is Adenosine triphosphate (ATP)
What does ATP consist of?
Adenosine (an organic molecule) attached to a string of three phosphate groups
What does ATP store the potential to react with?
Water- this reaction releases energy to be used by the cell
How many classes of large biological molecules are all living things made of?
Carbohydrates, lipids, proteins and nucleic acids
What are macromolecules?
They are large molecules and are complex
What are enzymes?
Enzymes are specialized macromolecules that speed up chemical reactions
What is a dehydration reaction?
It occurs when two monomers bond together through the loss of a water molecule
What is hydrolysis?
When polymers are disassembled to monomers by hydrolysis which is a reaction that is essentially the reverse of the dehydration reaction
What are carbohydrates?
They include sugars in the polymers of sugars
What are the simplest carbohydrates?
Monosaccharides, or simple sugars
What are carbohydrate macromolecules?
Polysaccharides, polymers composed the many sugar building blocks
What is the typical molecular formula for monosaccharide?
Multiples of CH2O
What is the most common monosaccharide?
Glucose
How are monosaccharides classified?
The number of carbons in the carbon skeleton in the location of functional groups
What does monosaccharide serve as?
A major fuel for cells
And
Raw material for building molecules
What is a monosaccharide?
A single sugar
What is a disaccharide?
It is formed when a dehydration reaction joins two monosaccharides
What is the Glycosidic linkage?
The covalent bond between two monosaccharides to form a disaccharide
Monosaccharide and disaccharide are simple sugars- true or false
True
Polysaccharides (three or more) are complex sugars. True or false
True
What are polysaccharides?
The polymers of sugars, have storage and structural roles
The architecture and function of a polysaccharide are determined by its?
Sugar monomers in the positions of its glycosidic linkages 
What is starch?
Storage polysaccharide of plants consists entirely of glucose monomers
What is glycogen?
It is a storage polysaccharide in animals
Where is glycogen stored?
Mainly and liver and muscle cells
What does the hydrolysis of glycogen in the cells result in?
Release of glucose when the demand for sugar increases
What is cellulose?
It’s a polysaccharide that is a major component of the tough wall of plants cells
What are lipids?
Lipids are the one class of large biological molecules that does not include true polymers
What are the unifying features of lipids?
They mix poorly, if at all, with water
Are lipids hydrophobic or hydrophilic and why?
Hydrophobic because they consist mostly of hydrocarbons which form nonpolar covalent bonds
What are the most biologically important lipids?
Fats, phospholipids, and steroids
What are fats constructed of?
From two types of smaller molecules glycerol and fatty acids
What is glycerol?
Glycerol is a three carbon molecule with a hydroxyl group attached to each carbon
What is a fatty acid?
It consists of a carboxyl group attached to a long carbon skeleton
_____________ vary in length (number of carbons) and in the number and locations of double bonds
Fatty acids
What are saturated fatty acids?
They have the maximum number of hydrogen atoms possible and no double bonds
What are unsaturated fatty acids?
They have one or more double bond
What are fats made from saturated fatty acids called?
Saturated fats
What state of matter are saturated fats?
They are solid at room temperature
True or false - most animal fats are saturated
True
What are fats made from unsaturated fatty acids called?
Unsaturated fats or oils
What state of matter are unsaturated fats or oils?
They are liquid at room temperature
True or false plant fat and fish fats are usually unsaturated
True
What contributes the most to cardiovascular disease?
Trans fats
What is the major function of a fat?
Energy storage
What do humans and other mammals do with their fat cells?
Store there long term food reserves
What other function do fat tissues have?
They cushion vital organs and insulate the body
What is a phospholipid?
It consists of two fatty acids in a phosphate group that are attached to a glycerol
Are the two fatty acid tails of a phospholipid hydrophobic or hydrophilic?
Hydrophobic
The phosphate group and it’s attachments form a __________
Hydrophilic head
What happens when phospholipids are added to water?
They self assemble into double layered structures called bilayers
What does a surface of a cell look like?
Phospholipids are also arranged in a bilayer with the hydrophobic tails pointing towards the interior
What does the structure of phospholipids result in?
A bilayer arrangement found in cell membranes
What are steroids?
They are lipids characterized by a carbon skeleton consisting of four fused rings
What is cholesterol?
It is a type of steroid, is a component an animal cell membranes and a precursor from which other steroids are synthesized
What may happen if there is a high level of cholesterol in the blood?
This may lead to cardiovascular disease
How much of the dry mass of the most cells do proteins account for?
More than 50%
What are enzymes?
They are proteins that speed up chemical reactions
What are other functions of proteins?
defense,
Storage,
Transport,
Cellular communication,
Movement,
Structural support
What do enzymes act as?
Catalysts 
Can enzymes perform their functions repeatedly?
Yes
What are proteins all constructed from?
The same set of 20 amino acids
What are polypeptides?
They are unbranched polymers built from these amino acids
What is a protein?
It is a biologically functional molecule that consists of one or more polypeptide
What are amino acids?
Amino acids are organic molecules with amino and carboxyl groups
Amino acids differ in their properties due to differing side chains called…
R groups
Amino acids are linked by covalent bonds called?
Peptide bonds
What is a polypeptide?
It is a polymer of amino acids
What does each polypeptide have?
A unique linear sequence of amino acids with a carboxyl end and an amino end
What does a specific activities of proteins results from?
Their intricate three dimensional architecture
What is a functional protein?
It consists of one or more polypeptide’s precisely twisted, folded, and coiled into a unique shape
What does a proteins structure determines?
How it will work
What is the primary structure of a protein?
Is its unique sequence of amino acids
What is a secondary structure?
It is found in most proteins, consists of coils and folds in the polypeptide chain
What is the tertiary structure?
It is determined by interactions among various side chains
What is the quaternary structure?
Results when a protein consists of multiple polypeptide chains
What do the coils and folds of secondary structure result from?
hydrogen bonds between repeating constituents of the polypeptide backbone
What are secondary structures typically positioned like?
A coil called a helix and a folded structure called a b pleated sheet
In a tertiary structure, the overall shape of a polypeptide results from?
Interactions between R groups
The interactions between R groups in a tertiary structure include-
Hydrogen bonds, ionic bonds, hydrophobic interactions, and Vanderwaals interactions 
What are disulfide bridges?
They are strong covalent bonds that may reinforce the proteins structure
What does a quaternary structure result from?
When two or more polypeptide chains form one macromolecule
What is an example of a quaternary structure?
Hemoglobin.
It is a globular protein consisting of four polypeptides, to Alpha and two beta chains
In addition to primary structure _________ and __________ can affect structure. 
Physical and chemical conditions
What can cause a protein to unravel?
Alterations in pH, salt concentration, temperature, or other environmental factors
What is it called when a protein loses its native structure?
Denaturation
A Denatured protein is ___________ ___________
Biologically inactive
What is a gene?
The amino acid sequence of a polypeptide is programmed by unit of inheritance called a gene
Genes consist of _______ which is…
DNA
A nucleic acid made of monomers called nucleotides
What do nucleic acids do?
The store transmit and help express hereditary information
What are the two types of nucleic acid?
Deoxyribonucleic acid (DNA)
Ribonucleic acid (RNA)
What does DNA and (m)RNA do?
What is this process called?
DNA directs synthesis of messenger RNA and through mRNA, controls protein synthesis. (Gene expression)
What is the flow of genetic information?
DNA—> RNA—> protein
What are nucleic acids?
They are polymers called poly nucleotides
What is each poly nucleotide made of?
Monomers called nucleotides
What does a nucleotide consist of?
A nitrogenous base, a pentose sugar, and one or more phosphate groups
What is the portion of a nucleotide without the phosphate group called?
Nucleoside
(Nucleoside = nitrogenous base + sugar)
What are the two families of nitrogenous bases?
Pyrimidines and purines
What are pyrimidines?
Cytosine thymine and uracil. They have a single six membered ring
What are purines?
Adenine and guanine. They have a six membered ring fused to a five membered ring
What is the sugar in DNA and what is the sugar in RNA?
Deoxyribose
Ribose 
What is a nucleotide?
Nucleoside + phosphate group
What are adjacent nucleotides joined by?
Phosphodiester linkage
What forms DNA double helix?
The two polynucleotides spiraling around an imaginary axis
What does the anti-parallel arrangement refer to for DNA’s structure?
The backbones run in opposite 5’ —> 3’ directions from each other 
Which bases in DNA pair up and form hydrogen bonds?
What is this process called?
Adenine and thymine
Guanine and cytosine 
Complementary base pairing
RNA, in contrast to DNA is _______ stranded.
Single
What does uracil replace in RNA?
Thymine
What else is replaced in RNA compared to DNA?
Deoxyribose is replaced by ribose
