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Atoms are the baic particles of ______
matter
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What are the smallest units of matter?
atoms
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Protons and neutrons reside in the ____ of an atom
nucles
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What is Atomic Number?
THe number of protons in an atom
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Each ______ includes all the atoms that have the same number of protons and thus the same _____________
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Within an atom, an ______________ surrounds the nucleus
electron cloud
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What is the mass number of an atom?
the total number of protons and neutrons in its nucleus
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What are Isotopes?
atoms of the same element whose nuclei contain different numbers of neutrons
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Electrons occupy an orderly series of _________, commonly illustrated as ___________
- energy levels
- electron shells
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The _______ in the outermost energy level determine an element's chemical properties
electrons
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Atoms can combine through chemical reactions that create _________
chemical bonds
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What is a molecule?
Any chemical structure consisting of atoms held together by covalent bonds
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What is a compound?
a chemical substance made up of atoms of two or more elements
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What is an ion?
atoms that have gained or lost electrons
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An __________ results from the attraction between ions
ionic bond
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What are Cations?
positively charged ions
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What are Anions?
Negatively charged ions
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Atoms that share electrons to form a molecule are held together by ________
covalent bonds
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A sharing of one pair of elections is a __________
single covalent bond
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A bond with unequal sharing of electrons is a
polar covalent bond
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What is a hydrogen bond?
a weak but important, force that can affect the shapes and properties of molecules
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What is the molecular weight of a molecule?
the sum of the atomic weights of its component atoms
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THe rules of _________ are used to describe chemical compounds and reactions
chemical notation
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Thre important chemical reactions in physiology
- Decomposition reactions
- Synthesis reactions
- Exchange reactions
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A chemical reaction occurs when _____ are rearranged to form one or more _______
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What is metabolism?
THrough metabolism, cells capture, store, and use energy to maintain homeostasis and to perform essential functions
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What is work?
The movement of an object or a change in the physical structure of matter
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Cells gain energy to power their functions by
catabolism
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WHat is Catobolism?
thre breakdown of complex molecules
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What is Anabolism?
The synthesis of new molecules
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At equilibrium, the rates of two opposing reactions are
in balance
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Enzymes catalyze specific biochemical reactions by
lowering a reactions activation energy
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What is Activation Energy?
the amount of energy required to start a reaction
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What is a catalyst?
compounds that accelerate chemical reactions without themselves being permanently changed or consumed
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Exergonic reactions...
release energy
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Endergonic reactions.....
absorb energy
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Inorganic compounds lack
carbon
-
Organic compounds contain
carbon
-
What are nutrients?
the essential elements and molecultes normally obtained from the diet
-
What are metabolites?
molecules that can be synthesized or broken down by chemical reactions inside our bodies
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Nutriends and metabolites can be broadly categorized as either _______ or __________
inorganic or organic compounds
-
Physiologic systems depend on _____
water
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Electrolytes are ________ compounds
inorganic
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Electrolytes undergo _______ in water to form ions
ionization
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Molecules that interact readily with water molecules are called
hydrophilic
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Molecules that do not interact readily with water molecules are called
hydrophobic
-
The pH of a solution idicates the....
concentration of hydrogen ions it contains
-
An acid releases
hydrogen ions
-
a base removes
hydrogen ions
-
What is the function of a buffer?
to remove or replace hydrogen ions in solution
-
Carbohydrates contain ______, ______, and ______ in a _________ ratio
- carbon, hydrogen, and oxygen
- 1:2:1 ratio
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Carbohydrates are most important as an ______ source for __________ processes
-
The three major types of carbohydrates
- monosaccharides ( simple sugars)
- disaccharides
- polysaccharides
-
Disaccharides and polysaccharides form from monosaccharides by
dehydration synthesis
-
Lipids contain a carbon to hydrogen ratio of
1:2
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The five important classes of lipids are
- fatty acids
- eicosanoids
- glycerides
- steriods
- phospholipds
- glycolipids
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Triglycerides consist of three ______________ attached by __________ to a molecule of glycerol.
- fatty acid molecules
- dehydration synthesis
-
3 facts about Steriods
- 1. Are components of plasma membranes
- 2. Include sex hormones and hormones regulation metabolic activities
- 3. Are important in lipid digestion
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Structural lipids that are componenets of micelles and plasma membranes
phospholipids and glcolipids
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Protiens are formed from ____________ and contain __________________________________
- amino acids
- carbon, hydrogen, oxygen, and nitrogen
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Seven important types of proteins are
- structural proteins
- contractiles proteins
- transport proteins
- uffering proteins
- enzymes
- hormones
- antibodies
-
Proteins are chains of
amino acids
-
What is a polypeptide?
a linear sequence of amino acids held together by peptide bonds
-
THe four levels of protein structure
- primary structure ( amino adic sequence(
- secondary structure ( amino acid interactions, such as hydrogen bonds)
- Tertiary structure ( complex folding, disulfide bonds ,and interaction with water molecules(
- Quaternary structure ( formation of protein complexes from individual subunits
-
Fibrous protiens are
enlongated, tough, durable, and generally insoluble
-
Globular proteins are
generally rounded and water soluble
-
the reactants in an enzymatic reaction are called
substrates
-
What are Cofactors?
ions or molecules that must bind to the enzyme before substrate binding can occur
-
What are Coenzymes
orgainc cofactors commonly derived from vitamins
-
THe shape of a protein determines its ____________
functional characteristics
-
DNA and RNA are
nucleic acids
-
What are Nucleic acids?
they store and process info at the molecular level
-
DNA stands for
deoxyribonucleic
-
RNA stands for
ribonucleic acid
-
What are nucleic acids?
nucleotides
-
Each nucleotide contains a ____, a ______, and a __________
- sugar
- phosphate group
- nitrogenous base
-
DNA contains the nitrogenous bases
- adenine
- guanine
- cytosine
- thymine
-
RNA cones the nitrogenous bases
- adenine
- guanine
- cytosine
- uracil
-
What is ATP?
a high-energy compound used by cells
-
THe most important high-energy compound is
ATP
-
Cells make ATP by
adding a phosphate group to ADP through phosphorylation
-
Chemicals from functional units called
cells
-
What is Metabolic turnover
the continuous removal and replacement of cellular organic molecules
-
Metabolic turnover allows cells to
change and to adapt to changes in their environment
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