digestion breaks food down to basic monomers
1. monosacharides
2. fatty acids
3. amino acids
4. nucleotides
anaeoribic
dont require oxygen
completed in cytoplasm
ex. fermentation
aerobic
require oxygen
completed in mitochondria
glycosis
starts from a simple Glucose "sugar"
breaking of the covalent bonds releases energy
occurs in cytoplasm
two types of glycosis
energy requiring 2 atp needed
non requiring
2 nahd formed
4 atp created
What is Acetyl-CoA
A two-carbon acetyl group linked to coenzyme A (a derivative of the B vitamin Pantothenic Acid
krebs cycle
occurs in the mitochondria
Pyruvate is broken down to CO2
More ATP is formed
More NADH and FADH2 are produced
Electron Transport Phosphorylation
Occurs in the mitochondria
NADH & FADH2 deliver electrons to electron transport systems
O2 receives the electrons to make H2O
Electron transport sets up H+ ion gradients
Flow of H+ down gradients powers ATP formation
Importance of Oxygen
Electron transport phosphorylation requires the presence of oxygen
Oxygen withdraws spent electrons from the electron transport system, then combines with H+ to form water
Fermentation Pathways
type of anerobic pathway
Begin with glycolysis
Do not break glucose down completely to carbon dioxide and water
Yield only the 2 ATP from glycolysis
Steps that follow glycolysis serve only to regenerate NAD+
Anaerobic Electron Transport
Carried out by certain bacteria
Electron transport system is in bacterial plasma membrane
Final electron acceptor is compound from environment (such as nitrogen), NOT oxygen (NOTE - Not the Same as Respiration!!!)
ATP yield is low
Functions of Blood
Transports oxygen and nutrients to cells
Carries carbon dioxide and wastes away from cells
Helps stabilize internal pH
Carries infection-fighting cells
Helps equalize temperature
Composition of Blood
Plasma (50-60% by vol.)
Water 91-92%
Proteins: albumin, antibodies, etc.
Solutes: ions, sugars, fats, amino acids, hormones, vitamins, gasses
Cellular portion (40-50%)
RBC's: O2 and CO2 exchange
WBC's: immune responses
Platelets: blood clotting
A. Human Heart
Double Pump:
Partition separates heart into left and right sides
atrium: receive blood from veins
ventricles: push blood into arteries
Each pumps blood through a different circuit
Each side has two chambers
upper atrium and lower ventricle
Cardiac Cycle
Diastole
relaxed
blood enters atria then ventricles
Systole:
contraction
1st atria
2nd ventricle
pushes blood out
Pulmonary Circuit
Short loop that oxygenates blood
Systemic Circuit
Longer loop that carries blood to and from body tissues
Hepatic Portal System
Carries blood from capillaries in digestive organs to capillaries in the liver
Allows liver to detoxify substances from digestive tract before they are carried to the body
Out-flow vessels
Arteries: main transporters of oxygenated blood
Arterioles: diameter is adjusted to regulate blood flow
Capillaries: diffusion occurs across thin walls
Lymphatic System
Functions:
Absorb water and plasma proteins from tissues and return it to the heart (leaked out from blood capillaries)
Absorbs fats from small intestines and transfer to general circulation
Carries pathogens and foreign cells to lymph nodes (disposal cen
Lymphoid Organs
Central to the body's defense
Tonsils
Thymus gland
Spleen
Ventilation
Movement of fluid or air around gas exchanging tissues
Removes low O2/high CO2 fluid or air; replaces with high O2/low CO2 fluid or air
Maintains steep gradient so concentration differences are high
Respiratory Cycle
Diaphragm constricts
External intercostal muscles contract
Volume of thoracic cavity increases; pressure decreases
Lungs expand
Air flows down pressure gradient into lungs