Chapter 3- The chemical building blocks of life Flashcards
The framework of biological molecules consist predominantly of _______ atoms bonded to other _______ atoms or to atoms of hydrogen, oxygen, nitrogen, sulfur, or phosphorus
Carbon
Because carbon atoms can form up to _______ covalent bonds, molecules containing carbon can form straight chains, branches, or even rings, balls, tubes, and coils
4
Molecules consisting only of carbon and hydrogen are called _______
Hydrocarbon
Because the oxidation of hydrocarbon compounds results in a net release of energy, hydrocarbons make good _______
Fuels
OH is called a _______ group
Hydroxyl
Are hydrocarbons polar or nonpolar?
Nonpolar
Organic molecules having the same molecular or empirical formula can exist in different forms called _______
Isomers
If there are differences in the actual structure of an isomers carbon skeleton, they are called _______ _______
Structural isomers
A form of an isomer that has the same carbon skeleton but differs in how The groups attached to this skeleton are arranged in space
Stereoisomers
A subcategory of stereoisomers, called _______, are actually mirror images of each other
Enantiomers
A molecule that has mirror image versions it’s called a _______ molecule 
Chiral
Two examples of enantiomers
D sugars and L amino acids
Biological macromolecules are traditionally grouped into what 4 things?
Carbohydrates, nucleic acids, proteins, and lipids
A long molecule built by linking together a large number of small, similar chemical subunits called monomers
Polymers
The nature of a polymer is determined by its constituent _______
Monomers
Nucleic acids are polymers of _______, and proteins are polymers of _______ _______
Nucleotides; amino acids
Polymers are built through _______ reactions and broken down by _______ reaction
Dehydration; hydrolysis
The process of positioning and stressing, termed _______, is carried out within cells by enzymes
Catalysis
In this reaction, hydrogen atom is attached to one subunit and a hydroxyl group to the other, breaking the covalent bond joining the subunits
Hydrolysis
_______ can distinguish structural and stereoisomeric difference of the sugars
Enzymes
_______ groups have definite chemical properties that they retain no matter where they occur
Functional
Chemical reactions involve the formation or breaking of chemical _______
Bonds
Lipids are macromolecules formed through _______ synthesis
Dehydration
Formation of large molecules by the loss of water
Dehydration synthesis
Breakdown of large molecules by the addition of water 
Hydrolysis
The extent of the chemical reaction is influenced by what three factors?
Temperature, concentration of reactants and products, catalysts 
Molecules with a 1:2:1 ratio of carbon, hydrogen, and oxygen
Carbohydrates
Because carbohydrates contain many carbon hydrogen bonds, which releases energy when they are rearranged, they are well suited for _______ storage
Energy
The simplest of carbohydrates are _______
Monosaccharides
The most important 6-carbon sugar used for energy storage is _______
Glucose
Glucose can exist in and two different forms, _______ and _______
Alpha and beta
Enzymes can distinguish structural and stereo isomeric _______ of the sugars
Difference
Glucose can be linear or two different _______ configuration
Ring
_______ is a structural isomer that differs in the position of the carbonyl carbon
Fructose
_______ is a stereoisomer that differs in the position of -OH and -H groups relative to the ring
Galactose
Transport forms of sugars are commonly made by linking two monosaccharides together to form _______
Disaccharides
Disaccharides serve as effective reservoirs of _______ bc the enzymes that normally use glucose in an organism cannot break the bond linking the two monosaccharides subunits 
Glucose
When glucose forms a disaccharide with the structural isomer fructose, the resulting disaccharide is _______, or table sugar
Fructose
_______ is the form most plants use to transport glucose and is the sugar that most animals and humans eat
Sucrose
When glucose is linked to the stereoisomer galactose, the resulting disaccharide is _______, or milk sugar
Lactose
_______ are longer polymers made up of monosaccharides that have been joined through dehydration reactions
Polysaccharides
_______, a storage polysaccharide, consists entirely of alpha glucose molecules linked in long chains
Starch
_______, a structural polysaccharide, also consists of glucose molecules linked in chains but these molecules are beta glucose
Cellulose
Polysaccharides are two monosaccharides linked by _______ synthesis
Dehydration
Organisms store the metabolic energy Contained in monosaccharides by converting them into disaccharides, such as _______
Maltose
The starch with the simplest structure is _______
Amylose
The long chains of amylose tend to _______ up in water, a property that renders amylose insoluble
Coil
Most plant starch is a somewhat more complicated variant of amylose called _______
Amylopectin
The comparable to starch in animals is _______
Glycogen
_______ is an insoluble polysaccharide that contains branched amylose chains and has a much longer average chain length and more branches than plant starch 
Glycogen
Cellulose is a polymer of _______ glucose
Beta
_______ is the chief component of plant cell walls
Cellulose
The starch-hydrolyzing enzymes that occur in most organisms cannot break the bond between two beta glucose units because they only recognize _______ glucose linkages
Alpha
Cellulose cannot be broken down by most animals, which is why it is mainly used for structural purposes, but some animals are able to use it in their _______ tract
Digestive
The structural material found in arthropods and many fungi 
Chitin
When cross-linked by proteins, it forms a tough, resistance surface material that serves as the hard exoskeleton of insects and crustaceans
Chitin
The biochemical activity of a cell depends on production of a large number of _______, each with a specific sequence
Proteins
2 main varieties of nuclei acids are:
Deoxyribonucleic acid and ribonucleic acid
Genetic info is stored in _______ while RNA plays a variety of roles in the cell, including as short lived copies of genetic info used to direct synthesis of proteins
DNA;RNA
Nucleus acids are able to serve as templates for producing precise _______ of themselves; this allows genetic info to be preserved during cell division and reproduction
Copies
As a carrier of info, the form of RNA called _______ RNA consists of transcribed single stranded copies of portions of the DNA
Messenger
_______ RNA serves as the blueprint for specifying the amino acid sequences of proteins
Messenger
Nucleic acids consist of long polymers of repeating subunits called _______
Nucleotides
Each nucleotide consists of three components:
A 5-carbon sugar
A phosphate group
A nitrogenous base
Nucleotides have 5 types of nitrogenous bases:
Adenine
Guanine
Cytosine
Thymine (DNA only)
Uracil (RNA only)
_______ are formed by joining the phosphate of 1 nucleotide to a hydroxyl group of the sugar of another nucleotide in a dehydration reaction
Polynucleotides
A _______ _______ is a chain of 5-carbon sugars linked together by phosphodiester bonds with a nitrogenous base protruding from each sugar
Nucleic acid
A spiral shape is called a _______
Helix
A helix composed of 2 chains is called a _______ _______
Double helix
Adenine pairs with _______(DNA) or _______(RNA)
Thymine; uracil
Cytosine pairs with _______
Guanine
DNA contains _______ information for amino acid sequence of proteins
Coding
tRNA is:
Transfer RNA
mRNA is:
Messenger RNA
rRNA is:
Ribosomal RNA
The energy currency of the cell
Adenosine triphosphate(ATP)
Cells use the energy released by breaking down food molecules to synthesize _______
ATP
Nicotinamide adenine dinucleotide(NAD) and flavin adenine dinucleotide(FAD) molecules function as _______ carriers in a variety of cellular processes
Electron
_______ are the most diverse group of macromolecules, both chemically and functionally
Proteins
Proteins are composed of long, unbranched chains of _______ _______
Amino acids
Each chain of _______ is a polypeptide of varying amino acid length
Protein
7 main biological functions of proteins:
Enzymes catalysis
Defense
Transport
Support
Motion
Regulation
Storage
Most _______ are 3 dimensional globular proteins that fit snugly around the molecules they act on
Enzymes
The transport protein, _______, transports oxygen in the blood
Hemoglobin
Protein fibers play _______ roles like keratin in hair, fibrin in blood clots, and collagen
Structural
Muscles contract through the sliding motions of 2 kinds of protein filaments: _______ and _______
Actin;myosin
Calcium and iron are stored in the body by binding as ions to storage _______
Proteins
The specific _______ of amino acids determines the proteins structure and function
Order
The unique character of each amino acid is determined by the nature of the _____ group
R
The amino and carboxyl groups on a pair of amino acids can undergo a dehydration reaction to form a _______ bond
Covalent
The covalent bond that links to amino acids is called a _______ bond
Peptide
Peptide bonds are not free to _______ because of the partial double bond
Rotate
The bond that forms when amino acids are joined by dehydration synthesis:
Peptide
The bond that is formed between the amino end(N) and carboxyl end(C) of each amino acids
Peptide
An unbranched chain of amino acids linked by peptide bonds is called a _______
Polypeptide
If a polypeptide can fold into a structure with some function, such as the antimicrobial enzyme lysozyme in your saliva, we also call it a _______
Protein
X-rays can be passed through a crystal of _______ to produce a diffraction pattern
Protein
What are the four levels of hierarchy in proteins?
Primary, secondary, tertiary, and quaternary
The _______ structure of a protein is its amino acid sequence
Primary
The _______ structure of proteins can fold into a pleated sheet or turn into a helix
Primary
The two kinds of ______ structures and proteins create regions of the proteins that are cylindrical and planar
Secondary
Interactions between the amino acids a variable group create _______ structures
Secondary
Helix= ______ spiral
Coiled
Sheet= _______ structure
Planar
The final folded 3D shape of a globular protein is called its _______ structure
Tertiary
_______ structure contains regions that have secondary structure determines how these are further arranged in space to produce the overall structure
Tertiary
When proteins are unfolded, they are being _______
Denatured
Protein structure that is an interaction of individual protein trend to create proteins with two or more polypeptide chains
Quaternary
Common elements of secondary structure interacting with each other
Motifs
Functional units within a larger protein, are usually made of different motifs
Domains
_______ proteins have the ability to company protein on its path to a properly fold and state
Chaperone
Improper folding of proteins can result in _______
Disease
Chaperone proteins are extremely _______, unlike most proteins
Flexible
If a proteins environment is altered, protein may change shape or unfold completely, which is called _______
Denaturation
Denatured proteins are usually biologically _______ 
Inactive
For proteins with quaternary structure, the subunits may be _______ without losing their individual tertiary structure, not to be confused with denaturation 
Disassociated
_______ are a somewhat loosely defined group of molecules with one main chemical characteristic: they are insoluble in water
Lipids
Lipids have a high proportion of nonpolar C—H bonds, which causes the molecule to be _______
Hydrophobic
Examples of lipids:
Fats, oils, waxes, and even some vitamins
How many lipids are built from a simple skeleton made up of two main kinds of molecules: _______ _______ and _______
Fatty acids; glycerol
_______ are composed of one glycerol and three fatty acids
Triglycerides
The three fatty acids of a triglyceride do not need to be _______
Identical
The chain _______ of a fatty acid varies 
Length
A _______ fat has no double bonds between carbon atoms
Saturated
The type of fat that has a higher melting point and an animal origin:
Saturated
_______ fat has one or more double bonds
Unsaturated
The type of fat that has a low melting point and a plant origin:
Unsaturated
Steroids, another class of lipid, are composed of _______ carbon rings 
4
_______ are excellent energy storage molecules
Fats
The basic structure of a phospholipid includes three kinds of subunits:
Glycerol, 2 fatty acids, and a phosphate group
The _______ molecule can be thought of as having a polar head at one end and two long, very nonpolar tails at the other
Phospholipid
_______ are lipid molecules oriented with polar head toward water and nonpolar tails away from water
Micelles
Lipid bilayers are the basic framework of biological _______
Membranes
Hydrophilic heads(polar) point _______ associated with water(nonpolar)
Outward
Hydrophobic tails(nonpolar) point _______ toward each other
Inward
