Energy Transfer Flashcards
what happens to energy stored within covalent bonds
- can be released through hydrolysis
- stored in carrier molecules
what is the pathway of energy of sunlight to energy useful for cells
what is the energy currency of cells
ATP (adenosine triphosphate)
how does ATP form energy
- terminal phosphate is easily hydrolyzed
- energy released through hydrolysis can be used to fuel cellular processes
what happens when ATP goes to ADP
- energy released through hydrolysis can be used to fuel cellular processes
- released phosphate may be transferred to another molecule (which can change the shape and function of that molecule)
where do the three stages of catabolism of food take place
- stage 1 outside of the cell
- stage 2 mostly in cytosol
- stage 3 mitochondria
what happens in stage 1 of food catabolism
- food is broken down into simple subunits
- proteins to AA
- polysaccharides to simple sugars
- fats to fatty acids + glycerol
what happens in stage 2 of food catabolism
- simple subunits are converted to acetyl CoA (glucose to pyruvate to acetyl CoA via glycolysis)
- limited amounts of ATP and NADH produced
what happens in stage 3 of food catabolism
- acetyl CoA is converted to H2O and CO2 (oxidative phosphorylation)
- large amounts of ATP produced
what are the inputs and outputs of glycolysis
- input
- 2ATP
- output
- 2 NADH, 4 ATP, 2 pyruvate
what is the net result of glycolysis
- 2 NADH
- 2 ATP
- 2 pyruvate
what is substrate-level phosphorylation
glycolysis
what is the NADH produced in glycolysis used for
used later in oxidative phosphorylation
what is gluconeogenesis
- process to store and increase available glucose
- builds glucose molecules from pyruvate
- essentially the reverse of glycolysis
what are the 3 main steps in glycolysis
- energy investment to be recouped later
- cleavage of 6C sugar to 3C sugar
- energy generation
what is the input and output of gluconeogenesis
- input
- 4 ATP, 2GTP, 2 pyruvate, 2NADH, 6H2O
- output
- glucose, 4ADP, 2GDP, 2NAD+, 2H+
how is gluconeogenesis driven
through feedback regulation of two enzymes: phosphofructokinase and fructose 1,6-biphosphatase
what activates/ inhibits glycolysis and gluconeogenesis
- ADP, AMP, and phosphate activate glycolysis and inhibit gluconeogenesis
- ATP inhibits glycolysis and activates gluconeogenesis
what do phosphofructokinase and fructose 1,6-biphosphatase do
- phosphofructokinase catalyzes the phosphorylation of fructose 6-phosphate to form fructose 1, 6-bisphosphate in step 3 of glycolysis
- fructose 1,6-bisphosphatase removes the phosphate from fructose 1,6-bisphosphate in gluconeogenesis
how is glucose stored in animal cells vs plant cells
- animal cells glycogen
- plant cells starch
Glycogen is synthesized by _______ and broken down into glucose by ________
- glycogen synthase
- glycogen phosphorylase
how is glycogen synthesized
by glycogen synthase
how is glycogen broken down into glycose
by glycogen phosphorylase
what is the primary source of ATP in oxygen-limited conditions
glycolysis
what is the primary source of ATP in anaerobic organisms
glycolysis
how can pyruvate be broken down, and where
- via fermentation
- in the cytosol