Biology Study Essay

Cellular Respiration how humans derive energy from food
ATP is the energy currency
C.R. converts glucose  energy
Can be anaerobic (no O2) or aerobic (O2)
C6H1206 +602 6C02+6H20+ATP
Glucose + water  carbon dioxide + water + energy
Homeostasis keeps the body at 37 degrees
All animals use C.R.
The attachment of P to ADP is controlled by enzyme
Can use other things other than glucose for C.R such as carbohydrates, proteins, fats, lipids.
Store glucose in the liver as glycogen
1 glucose molecule yield heat and 36 – 38 ATP molecules
ATP is a specific type form of stored energy
Fermentation
Fermentation occurs in the absence of oxygen.
Produces lactic acid (animals) or alcohol and carbon dioxide (in plants and microorganisms)
Produces no ATP, however prevents accumulation of pyruvate, thus allowing glycolysis to continue.

Fermentation equation
Glucose  lactic acid + 2 ATP (glycolysis) Glucose  alcohol + carbon dioxide + 2 ATP (glycolysis)

Do different animal produce more ATP then humans?
C.R.
Glycolysis 2 ATP
Krebs cycle 2 ATP
Electron transport chain The rest
Glycolysis
Occurs in the cytoplasm
Does not require oxygen
Products of glycolysis  pyruvate
Glucose converted into 2 pyruvate
2 ATP (input)  4 ATP (output) [net yield of 2 ATP]
2 pyruvate out put
2 NADH (used to power more ATP production later)
Pyruvate  converted into lactic acid when built up.
Krebs
Occurs in the mitochondria matrix (fluid medium in the middle of the mitochondria)
Occurs in the inner membrane of the mitochondria
Outputs carbon dioxide and hydrogen atoms
20 loaded receptors produced
NAD & FAD – electron transport molecules/ taxis pick up energised hydrogen molecules.
Produces many electron transport molecules (main purpose)
Require oxygen?
Electron Transport chain
NADH and FADH made in the Krebs cycle, their electrons will provide the energy that will work as pump along a chain of channel proteins across the inner membrane of the mitochondria (cristae)
Produces water and large amount of ATP
Occurs in the inner membrane of the mitochondria (cristae)
Forms another 32 ATP
Requires oxygen

Remove carbon dioxide, water,
The kidney respond to high levels of water in blood
Maintain
37 degrees
Glucose level
Osmoregulation

Homeostasis
Key balance
Water content (osmoregulation)
Ion content
Temperature (little variation)
Blood glucose concentration (little variation)
O2 CO2
The kidneys respond to higher levels of water in the blood plasma by producing a large volume of urine, which is also more dilute.
Kidneys remove  water, urea, glucose and salts (maintain homeostasis). Return all the glucose, and resorb as much water and salts as needed, the rest is urea.
Pancreas monitors and controls glucose levels.
Pancreas produces a hormone called insulin. Causes glucose to move from the blood to the cells.
Blood glucose  more insulin is released  glucose moves into cells  reducing blood glucose level in the blood.
Blood glucose  less insulin is released  glucose moves into cells  raises blood glucose level

Homeostasis and regulation is carried out by hormonal and nervous systems.
Animals respond based on sensory information  received from all parts of the body  which are then enacted by muscles and glands

Concentration gradient is essential to maintain homeostasis

O2  cell – following concentration gradient.
O2 concentration kept  inside the cell due to cellular respiration
O2 concentration kept  by constant supply from the lungs
O2 moves from  concentration outside cell to  concentration inside the cell
Exercise  high demand for O2 in cellular respiration   O2 inside the cell  concentration gradient increases  allows more oxygen to enter

Concentration gradient  glucose, CO2, H20, nutrients, amino acids, glycerol, fatty acids minerals.

CO2  in the cell.  Outside in capillaries  diffuse to the outside of the cell.  extracellular fluid taken into

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Biology Study Guide

Biology As The Study Of Life