Physiology Notes, Cell Structure and Metabolism
Cells come from pre-existing cells via division
Cells of all organisms fundamentally similar in structure, function, and metabolic functions
Contain hereditary information passed down during cell division
A cell’s volume increases faster than it’s surface area
Less surface area = less are for nutrient/waste diffusion
Solves via:
Dividing, getting thinner, form microvilli, store nutrients
(Microvilli – within small intestine)
Cells are highly organized, 3 basic parts
Plasma membrane
Selective barrier between contents and ECF
Regulates in/out
Nucleus, usually the largest within cell
Stores DNA
Cytoplasm, the interior of cell (minus the Nucleus), contains:
Organelles
Cytosol
Cellular Metabolism
Intermediary Metabolism, intracellular reactions
Degradation, synthesis, transformation of small organic molecules
Capturing energy provides raw materials for cell growth and existence
Anabolic processes
Favors SYNTHESIS of molecules for building organs and tissues
CONDENSATION/DEHYDRATION REACTIONS
Catabolic processes
Favor BREAKDOWN of complex molecules into simpler ones
HYDROLYSIS REACTIONS
ATP Production Pathways
Substrate-level phosphorylation
Formation of ATP by DIRECT transfer of phosphate groups to ADP
Fast source of ATP
Example: Creatine Phosphate, CP + ADP Creatine + ATP
Cellular respiration
Releases energy in bonds of glucose to produce ATP
1. Glycolysis
Breaks down 6C into two 3C pyruvate molecules, two ATP and two NADH
Pyruvate enters mitochondria
2. Transition Reaction
Pyruvate forms two acetyl CoA molecules, two CO2 and two NADH
Acetyl CoA enters Kreb’s
3. Tricarboxylic Acid Cycle (Kreb’s, Citric Acid Cycle)
Prepares H+ and e- molecules for entry to ETC, six NADH, two FADH2, two ATP and four CO2
NADH and FADH2 donate H+ and e- to ETC
4. ETC (Oxidative phosphorylation)
Synthesizes ATP (34)
5 membrane proteins (Complex 1-4, ATP Synthase) plus 2 mobile carriers
C1, NADH Dehydrogenase
C2, Succinate Dehydrogenase
Cells of all organisms fundamentally similar in structure, function, and metabolic functions
Contain hereditary information passed down during cell division
A cell’s volume increases faster than it’s surface area
Less surface area = less are for nutrient/waste diffusion
Solves via:
Dividing, getting thinner, form microvilli, store nutrients
(Microvilli – within small intestine)
Cells are highly organized, 3 basic parts
Plasma membrane
Selective barrier between contents and ECF
Regulates in/out
Nucleus, usually the largest within cell
Stores DNA
Cytoplasm, the interior of cell (minus the Nucleus), contains:
Organelles
Cytosol
Cellular Metabolism
Intermediary Metabolism, intracellular reactions
Degradation, synthesis, transformation of small organic molecules
Capturing energy provides raw materials for cell growth and existence
Anabolic processes
Favors SYNTHESIS of molecules for building organs and tissues
CONDENSATION/DEHYDRATION REACTIONS
Catabolic processes
Favor BREAKDOWN of complex molecules into simpler ones
HYDROLYSIS REACTIONS
ATP Production Pathways
Substrate-level phosphorylation
Formation of ATP by DIRECT transfer of phosphate groups to ADP
Fast source of ATP
Example: Creatine Phosphate, CP + ADP Creatine + ATP
Cellular respiration
Releases energy in bonds of glucose to produce ATP
1. Glycolysis
Breaks down 6C into two 3C pyruvate molecules, two ATP and two NADH
Pyruvate enters mitochondria
2. Transition Reaction
Pyruvate forms two acetyl CoA molecules, two CO2 and two NADH
Acetyl CoA enters Kreb’s
3. Tricarboxylic Acid Cycle (Kreb’s, Citric Acid Cycle)
Prepares H+ and e- molecules for entry to ETC, six NADH, two FADH2, two ATP and four CO2
NADH and FADH2 donate H+ and e- to ETC
4. ETC (Oxidative phosphorylation)
Synthesizes ATP (34)
5 membrane proteins (Complex 1-4, ATP Synthase) plus 2 mobile carriers
C1, NADH Dehydrogenase
C2, Succinate Dehydrogenase