Lecture 2 Flashcards
What takes place in ER (endoplasmic reticulum)?
In ER, many enzymes that help transforming chemicals to another form are produced. The metabolism of the chemicals takes place here
Why is cell membrane a good thing in this context (toxicology)?
The cell membrane keeps things outside/inside
What is the cell membrane made of?
Lipid bilayer (two layers of phospholipids). Outside: sensors (oligosaccharide, glycolipid) that cause a respons if it detects something. Inside: protein
What are phospholipids made of?
A polar head group (negative or positive) that is hydrophilic and one nonpolar lipid tail that is hydrophobic. These are amphiphilic since they have both hydrophilic (water loving) and lipophilic (fat loving) properties.
What is LD50?
Lethal dose to kill 50 % of the population
What does toxicity depend on? With words
- Molecular structure and chemical mechanism of toxicity
2. The situation where the toxic effect occurs
What does toxicity depend on? Chemically
- Physical form (low boiling point: more molecules in the air, bad if you inhale them)
- Purity (2,4,5-T often contain TCDD which is a very dangerous molecule)
- Route of expose (how the chemicals enter our body)
- Exposed organism (toxicity of a chemical depends on the organism)
- Sex (female, male)
- Age (kids: all enzyms has not been fully developed so it might lead to different metabolic pathways, older people: has less functioning metabolic pathways)
- Individual markers (each animal is different to another —> metabolism also differs)
What are the routes of exposure? i.e. how does the chemicals get into the body. 6 ways
- Or-Orl (Oral - food, drinks)
- Iv-Ivn (Intravenous - blood circulation)
- Ip-Ipr (Intraperitoneal - in abdominal cavity)
- In-Ihl (Inhalation - air)
- Sc-Scu (Subcutan - under skin)
- D-Skn (Dermal - on skin)
What is the typical order in effeciency of the routes of exposure?
Ivn>Ihl>Ipr>Scu>Orl>Skn
What is: LD? LC? TD? TC? LDlo or LDlow?
LD: lethal dose (mg molecule/kg bodyweight)
LC: lethal concentration (gas %)
TD: toxic dose (how many that get blind etc)
TC: toxic concentration (how many that get blind etc)
LDlo/LDlow: lowest dose that has ever been reported to cause an individual to die - should be lower than LD10
Why do you use lethal concentration and not just lethal dose?
It’s hard to know how much dose the animal got: if the chemical is gas it’s hard to say how much the animal inhaled
Toxicological concepts: What are acute and chronic effects?
Acute: symptoms comes fast
Chronic: long term effect
For example alcohol: can cause both acute and chronic effects.
- acute: drunk, dizzy, death
- chronic: long time drinking —> damage the liver
Toxicological concepts: What are delayed effects?
Symptoms that shows up a long time after.
For example:
- cancer: do not form right after exposure, it is often produced years after. It needs a series of transformed DNA, cells and mutation which takes time
Toxicological concepts: What is reversible and irreversible effects?
Reversible effects: effects that will disappear when the molecule is removed
Irreversible effects: damage that won’t disappear even when the chemical is removed
Toxicological concepts: What is local and systemic effects?
Local effects: for example, if you get a chemical on your skin and it burns
Systemic effects: chemical will be absorbed by the body and will be transported to the target organ in our body and it will affect our entire body