exam 1 class 2 and 3 Flashcards
homeo
similar
homo
same
transition between an organisms external environment and the intracellular fluid inside the cells
extracellular fluid (ECF)
buffer zone between cells and outside world
ECF
principle of mass balance
input=output
intake routes of the human body
mouth, nose, skin
output routes of the human body
skin nose kidneys
Homeostasis is not the same as
equilibrium
when external environment is stable and reaction or metabolic pathway has a constant rate
steady state homeostasis
rate or forward does not equal rate of reverse
rate of input=rate of output
steady state homeostasis
what happens when an external environment is not stable?
- temp changes
- organism responds ACTIVE REGULATROY CONTROL MECHANISMS
- balanced again
restricted to tissue or cell involved
local control
decrease in oxygen conc. in the tissues is an example of what?
local control
long distance pathway that uses the nervous system, endocrine system or both
reflex system
maintaining blood pressure in body is an example of what?
reflex control
response loop + feedback loop=?
reflex loop
input signal + integrating center + output signal +response =?
response loop
nervous/ endocrine system
integrating center
chemical signals, electrical signals or both
output signal
any cell of the body
target
the response “feeds back” to influence the input portion of the pathway
feedback loop
2 types of feedback loops
-positive feedback
- negative feedback
negative feedback loops is homeostatic or not homeostatic?
homeostatic
postitive are homeostatic or not homeostatic?
not homeostatic
in negative feedback…
the response loop shuts off
in positive feedback….
an outside factor is required to shut off the feedback loop
key factors about negative feedback
- most common
- oppositie to initial stimulus
- something becomes excessive or deficient, negative feedback occurs moves back to correct value in homeostasis
key factors about positive feedback
- less common
- in the direction to initial stimulus
- response reinforces the stimulus rather than decreasing or removing it, sends regulated variable even farther from its normal value- outside event must occur to stop loop
examples of positive feedback
loss of blood
blood clotting
childbirth
reflexes that have evolved for the body to predict a change that is about to occur and starts the response loop anticipation of the change
feedforward control
energy released from food is shown in the variation of the temperature of the water
bomb calorimeter
cells release energy in many small reactions called?
oxidative phosphorylation
electrons are transferred from one molecule to another and change the composition and energy content of the donor and the acceptor
oxidation
food molecules act as?
electron donors
products of the reaction has ________ energy content than the donor molecule that proceeded it in the pathway
lower
when carbon atoms are fully oxidized what happens?
they are released as waste in form of CO2
how is energy from food stored
ATP
1 mole of ATP=?
7200 calories
enzymes?
lower activation energy
3 major pathways
- glycolysis
- TCA cycle (krebs cycle)
- oxidative phosphorylation (electron transport chain)
to start glycolysis what do you need
glucose, ATP and NAD+
what is the end product of cellular respiration
net 30- 32 ATP per glucose
what is the main contribution of glycolysis and the citric acid cycle?
high energy electrons carried by NADH and FADH2 to the electron transport system in the mitochondria
what is the two equations of a glucose molecule
slide 12 of class 3
gylco? lysis?
sugar splitting
- pathway that does not require oxygen
- has 10 reactions total
glycolysis
1-5 of glycolysis
energy requiring phase
6-10 glycolysis
energy releasing phase
Is glycolysis pathway endergonic or exergonic?
exergonic
what steps of glycolysis uses ATP?
1 and 3
what steps of glycolysis make ATP and NADH?
6, 7, 10
glycolysis total
converts one six-carbon molecule of glucose into two three-carbon molecules of
pyruvate
net products= are two molecules of ATP and two molecules of NADH
where does glycolysis take place
in the cytoplasm
where does citric acid cycle take place
in the mitochondrial matrix
oxidative metabolism occurs where ?
in the internal folds of the mitochondria (cristae)
connector that links glycolysis to the rest of cellular respiration
pyruvate oxidation
step 1 of pyruvate oxidation
adequate oxygen and then pyruvate is moved to the mitochondria
step 2 of pyruvate oxidation
pyruvate reacts with coenzyme A and produces acetyl CoA, one NADH, and one CO2
step 3 of pyruvate oxidation
acetyl CoA has two parts a 2- carbon acyl unit which came from a pyruvate and coenzyme A
