Medicine Level 1 Physiology: Cell Transport SGD Report

1. CELL TRANSPORT
TASK 3

2. BODY WATER
• Water provides a fluid environment for communication and
molecular transport throughout the body.
• Person’s hydration: water conducts electricity;
↓ hydration lvl. = ↑ resistance to electrical flow through the body
• Total body water (of 70 kg) is approx. 40 L (obese – as low as 45%).
• Distributed among fluid compartments

3. 3.1. CHEMICAL COMPOSITION OF
INTRACELLULAR AND EXTRACELLULAR FLUID
• Extra (Table)
• Intra

4. INTRACELLULAR FLUID EXTRACELLULAR FLUID
• liquid found inside cells –
cytosol
• cytosol - complex mixture of
substances: proteins, ions, and
organelles dissolved in water
• or EXTRACELLULAR FLUID
VOLUME (ECFV)
• body fluid outside of cells
• consists: plasma, interstitial,
and transcellular fluid

5. INTRACELLULAR FLUID EXTRACELLULAR FLUID
CHEMICAL COMPOSITIONS
• Cytosol – 70% water
• pH 7.4
• ↑ amount of charged
macromolecules such as proteins
and nucleic acids than outside
• Plasma – 95% water
• ↑concentration Potassium ion
• ↓ concentration Sodium ion
• Cations: Sodium, Potassium,
Calcium
• Anions: Chlorine, Hydrogen
Carbonate
• Contains: proteins, glucose,
clotting factors, minerals,
hormones, CO2

6. 3.2 DIFFERENTIATE BETWEEN
DIFFUSION AND ACTIVE
TRANSPORT

7. DIFFUSION ACTIVE TRANSPORT
DEFINITION
passive movement of molecules along a
concentration gradient of higher
concentration to a lower concentration.
movement of particles across a cellular
membrane from a lower to a higher
concentration by the use of metabolic
energy.
METABOLIC ENERGY (main difference)
which does not require metabolic energy
in order to transport molecules across
the cell membrane.
requires metabolic energy in the form of
ATP for the transportation of molecules
across the cell membrane.
FUNCTIONS
maintains a dynamic equilibrium of
water, gases, nutrients, and wastes in
and out of the cell.
allows the transportation of molecules
like nutrients and wastes against the
concentration gradient.

8. DIFFUSION ACTIVE TRANSPORT
EQUILIBRIUM
No net movement of molecules is
observed after the establishment of
equilibrium on either side of the
membrane.
No equilibrium of molecules is
established in active transport.
TYPES OF PARTICLES
Water, oxygen, carbon dioxide, small
monosaccharides, sex hormones and
other small, hydrophobic molecules
Proteins, ions, complex sugars, and large
cells
EXAMPLE
Oxygen moving from the airways and
diffusion of molecules from the blood to
the cells through the interstitial fluid
Taking up nutrients, endocytosis,
exocytosis, sodium/potassium pump,
and secretion of a substance into the
blood stream