1. Directional terms, Homeostasis and Body Chemistry Flashcards
https://use.ob3.io/#/57365630-56de-11ec-851a-000000000000/
define ion
an electrically charged atom (gained or lost an electron)-
electrolytes are substances that dissociate into ions, in aquous solution (water pulls apart the ionic bond)
define pH
measures the amount of H+ in a solution
low pH (\<7) = acidic (lots of H+) high pH (\<7) = basic (lots of OH)
Describe the structure of an atom
Atom contains 3 types of subatomic particles- protons, electrons and neutrons.
Protons and Neutrons reside within the nucleus of the atom, and make up the mass of the atom (electron mass is negligible).
Electrons orbit around the nucleus in energy shells.
Protons have a positive charge, neutrons have no charge. Electrons have a negative charge
Each energy shell has a specific # of electrons that can orbit. The outer shell is called the valence shell, which determines the chemical properties of the atom.
Element’s weight is based on Protons + Neutrons (note electrons have no weight)
Electron’s atomic number is # of Protons (which is therefore same # of Electrons, for neutral atom)
Sometimes an atom with same number of proton (i.e. same element) can have different number of neutrons, forming isotope
explain the importance of buffers in the regulation of pH
body has different fluids that have very specific pH levels, to support function (e.g. acidic gastric juice helps break down food and kill microbes in stomach)
body is very sensitive to pH levels- important it sits within narrow limits
body naturally produces acids / base through normal metabolic processes, that disrupt the pH levels of different fluids
buffers are used to couteract increase of acid / base, through binding to H+. this process is reversible, so buffer can continually respond to changes in acidity / base through releasing/ accepting H+
this maintains pH levels within normal limits
Buffers can only work if there is a viable way to excrete the excess acid/base - so buffer + excretory system must work together
- Lungs- too much C02 increases the acidity of the body, so lungs support pH homeostasis by increasing / decreasing amount of CO2 released, as pH levels change. (when pH drops (too much H+) the lungs increase rate of respiration
- kidneys - can adjust how much H+ / OH- is reabsorbed / released
Blood pH is between 7.35-7.45.
- acidosis- when blood pH is <7.35. More common as body tends to be more acidic. occurs when body has respiratory issues (Cannot release CO2 which accumulates, thus increasing H+) / renal issues affecting excretion of H+
- alkalosis - when blood pH is >7.45. When body has released a lot of acid - e.g. excess vomiting / diaorrhea.
Discuss matter- how does it bond, what can it form
types of bonds
- ionic bonds- atoms give / take electrons to become ions (cations (give up e) / anions (take e))
-
covalent bonds- atoms share electrons
- non-polar- electrons shared equally
- polar- electrons shared unequally
Types of molecules formed
- elemental molecules +2 same atoms)
- compounds with +2 different atoms
Define the term internal environment
- water based medium in which body cells exist.
includes fluid within Cells (intracellular) surrounded by intercellular fluid, from which they absorb oxygen / nutrients and release waste- these are then absorbed / excreted into blood
Intracellular- ~70%
Intercellular - 30% (23% Interstitual, 7% plasma/other fluid)
define homeostasis
body’s ability to keep internal environment within relatively constant state, regardless of changes in the external environment. includes homeostasis of temperature, blood pressure, pH, glucose levels
Describe carbohydrates
organic molecules- CHO- carbon, oxygen, Hydrogen (1:1:2)
dissolve in water
three types
- Monosaccharides (E.g. glucose / fructose)
- Disaccharides
- Polysaccharides
- starch (plant storage)
- cellulose (used for cell walls)
- glycogen (animal storage)
- preferred source of energy for body
Describe lipids
diverse- all hydrophobic.
CHO (less O than Carbohydrates) + some have nitrogen / phosphorus
4 types
- triglyceride- fats and oils - Glycerol + 3 Fatty acids
- Phospholipid - 2 fatty acids + phosphate (hydrophilic)
- steroids (form cholesterol, bile salts, vit d synthesis, hormones)
- eicosanoids e.g. prostaglandins
Describe proteins
basic structural unit of tissues and hormones / enzymes
made up of enzymes
CHO and Nitrogen; plus nitrogen ‘R’ group which gives AA it’s unique property
20 used in principal building blocks of protein
can only be sourced externally, thus body needs to consume wide range of AA
Peptides - <10
polypeptides - 10>x<50
proteins- >50 AA’s joined together by peptide bonds
Describe Nucleic acids
Largest molecules- made up of nucleotide units (Sugar, nitrogen base, phosphate)
2 TYPES
- DNA- carry all genetic info to inform protein synthesis / when it will occur. Replicates itself before cell division
- 2 chains of Nucleotides, Bases are A,T,C,G
- RNA - involved in protein synthesis under direction of DNA
- 1 chain of nucleotides, bases are A,U,C,G
describe Adenosine Triphosphate (ATP)
organic compound
ATP stores energy in it’s bonds, which can fuel cell function
Carbs, lipids and proteins can undergo catabolic reactions to synthesize ATP
Describe chemical nature of enzymes
proteins. Biological catalysts (speed up reaction, but they themselves are not changed)
very selective and only catalyse one specific reaction
define diffusion
passive movement of molecules from H to L concentration- mainly in gas / liquid / solution
results in equal concentration on both sides of membrane
hydrophobic tails of cell membrane prevent free movement, but diffusion occurs when
- substance is lipid soluble
- small enough to pass through membrane channel
- assisted by carrier protein in the membrane
define osmosis
diffusion of water across semi permeable membrane, whereby particles can’t permeate. so you may be left with unequal water amount on each side of membrane.
osmosis causes blood cells to swell, when you drink lots of water so cells / interstitual fluid are isotonic
