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because cells are 70% water, most of the reactions in the body happen
in aqueous solutions
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reactions in cells happen at a very slow rate and use
enzymes to speed them up to where they need to be
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catabolism
- the breaking down of elements into sub units
- uses energy
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anabolism
- the putting together of small molecules to one large one
- a gain in energy (endothermic)
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enzymes
proteins that funcion as biological catalysts and permit reactions to occur rapidly at normal body temperature
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substrate
substance an enzyme acts on
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What do enzymes do?
- lower activation energy in a reaction
- facilitate molecular interactions (bring them closer together)
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Process of an enzyme action
- the substrate approaches the active site on the enzyme
- the substrate binds to the active site (very specific like key)
- enzyme breaks covalent bonds and monomers release via hydrolysis
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Key fact of enzymes
- they remain unchanged in the reaction and are ready to repeat the process
- they work very fast
- they can change shape easily with conformation change
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metabolic pathways
chain of reactions with each step usually catalyzed by a different enzyme
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How are metabolic pathways regulated
- activation or deactivation of the enzyme
- cells can turn on or off
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cofactors
- inorganic partner of enzyme
- binds to enzyme and induces change in its shape, which activates the active site
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coenzymes
orgainc cofactors
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Nucleotides
- nitrogenous base
- sugar
- phosphate group
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most common nucleotide
- ATP
- adenine ribose phosphate
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ATP
- the body's most important energy transfer molecule and cells cant survive without
- stores energy that is gained from exergonic reactions
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ATP energy
holds energy in covalent bonds in the 2 and 3 bond of phosphates
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phosphorylation
- addition of free phosphate group to another molecule
- carried out by kinases
- constantly making ATP in body
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glycolysis
the transformation of glucose (6C) to pyruvic acid 2 (3C) and 2 ATP formed
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anaerobic respiration
transition of pyruvic acid to lactic acid
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aerobic respiration
- use of oxygen to convert pyruvic acid to ATP and CO2 and H2O
- forms 36 ATP molecules
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Where is ATP made?
in the mitochondria
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enzyme regualtions
the cell controls how many molecules each enzyme makes
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alosteric control
- when a molecule other than one of the substrate binds to an enzyme at a special regulatory site outside the active site
- this caused a change in conformation of the enzyme and it not to function
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feedback inhibition
something (inhibitor) binds to active site to activate site or cause no reaction
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protein phosphorylation
- protein won't function with phosphate addition
- there are active and inactive forms of enzymes
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negative regulation
prevents an enzyme from acting and stops the reaction
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positive regulation
an enzyme's activity is stimulated by a regulatory molecule and the reactions speeds up
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active site
region of an enzyme surface to which a substrate molecule binds in order to undergo a catalyzed reaction
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carbohydrate metabolism
all ozidative carbohydrate consumption is a matter of glucose catabolism or break down to CO2 and H2O
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What is the function of a carbohydrate metabolism reaction?
- to transfer energy from glucose to ATP
- not to produce CO2 and water
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What are the 2 steps of glycolysis
- 1-energy investment phase where 2xATP are converted to 2xADP
- 2-energy generation where 4ADP are converted to 2xATP and 2xNAD+ are converted to NADH
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glucose catabolism
a series of small steps, each controlled by a separate enzyme in which energy is released in small managable amounts and as much as possible is transferred to ATP and the rest is released as heat
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What 3 major pathways make ATP
- glycolysis
- anaerobic respiration
- aerobic respiration
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coenzymes
- remove electrons from intermediate compounds
- enzymes transfer the H enzymes to coenzymes
- coenzymes donate H later in reaction
- these are helpers that enzymes NEED
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coenzyme examples
- NAD+
- NAD+ +2H+ = NADH + H+
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mitochondria
- organelles specialized for synthesizing APT
- the powerhouses of the cell
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What are the components of the mitochondria
the cristae and the matrix
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mitochondria matrix
- contains ribosomes, enzymes for ATP
- the space between cristae
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cristae
- inner membrane that has folds
- (mitochondria has 2 membranes)
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Need to know the chart of the ATP production!
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metabolism is highly organized
many cells have more of certian traits that others based on the function
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molecules are comprised of
atoms
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organelles are comprised of
molecules
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cells are composed of
organelles
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tissues are composed of
cells
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organs are composed of
tissues
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organ systems are composed of
organs
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organisms are composed of
organ systems
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organism
a single, complete individual
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organ system
human body is made of 11 organ systems
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organ
structure composed of 2 or more tissue types that work together and carry out particular function
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tissue
a mass of similar cells and cell products that form discrete region of an organ and performs a specific function
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cells
the smallest unit of an organism that carry out all the basic functions of life
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cytology
the study of cells and organelles
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organelles
microscopic structures in a cell that carry out its individual function
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molecules
make up organelles and other cellular components
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atoms
the smallest particles with unique chemical identities
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reductionism
the theory that a large, complex system such as the human body can be understood by studying its simpler components
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holsim
there are emergent properties of the whole organism that cannot be predicted from the properties of the separate parts
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exploratory surgery
open body and take a look inside
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medical imaging
viewing the inside of the body without surgery
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radiology
branch of medicine converned with imaging
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gross anatomy
study of structures that can be seen with the naked eye
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histology
examination of cells with microscope
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ultrastructure
the molecular detail seen in electron microscope
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histopathology
microscopic examination of tissues for signs of disease
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anatomical variation
not 2 humans are exactly alike, there are variations in the types of organs and the organ locations
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neurophysiology
physiology of nervous system
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endocrinology
physiology of hormones
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pathophysiology
mechanisms of disease
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comparative physiology
limitations on human experimentation like animal testing
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homeostasis
the body's ability to detect change, activate mechanisms that oppose it, and thereby maintaining relatively stable internal conditions
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claude bernard
discovered constant internal conditions regardless of external conditions
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walter cannon
coined the term homeostasis
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loss of homeostasis causes
illness or death, you need a state of balance
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what are the 3 components of a feedback loop
- receptors-sense changes in the body
- control center-make a decision and direct response
- effector-carries out the final corrective action to restore homeostasis
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Negative feedback loop
- blood pressure
- body temperature
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positive feedback loop
self amplifying cycle and a normal way of producing rapid changes (blood clotting, child birth, fever, protein digestion)
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