Paper 2 Flashcards
What is the Mambrane structure?
The mambrane is made up of a phospholipid bilayer (two-layer phospholipid), they are singular molecules made 2 hydocrabon chains. They have two parts: hydrophilic layer (blend with water) the inside layer, and hydrphobic (dont blend with water) the outside layer. They are Amphipatic molecules.
Which parts of the mambrate structure is hydrophobic and hydrophilic?
Head is hydrophilic and the tails are hydrophobic.
What is it called when molecules are both hydrophilic and hydrophobic?
Amphipatic molecules. These can be Phospholipids and Colesterol.
What is the Endosymbiotic theory?
explains how complex eukaryotic cells evolved from simpler prokaryotic cells. It sugests that ancient prokaryotic cells started to live inside a larger host cell in a mutually benefitial relatioship. Over time these internalized cells became permanant and evolved into organells like mitochondria and choloplast. Evidence: they have their own DNA, they have double membranes, they reproduce independently and their oval shape is similar to bacteria cells.
What is the function of Cholesterol in the Cell Mamabrane?
Chlolesterol is a component in animal cell´s mambrane. It is amphipatic molecule. Its function is to control the fluidity of the cell mambrain, by stalilizing components that reduces the fluidity, preventing it from becoming too rigid in cold temperatures and too fluid in warm temperatures. Also provides stability by strenghening the mambrane by fitting between phopholipids, reducing permeabillity to small water soluble molecules
Describe Lipids and carbohydrates as a source of energy:
Lipids source of energy are:
- fats (solid)
- oils (liquid)
Lipids are:
- High-energy storage. They store more energy per gram compared to carbohydrates
- Long-term energy source. They are stored in tissue and used when carbohydrate reserves are low
- Slow energy release. They are broken down to produce ATP, but this process is slower than carbohydrates metabolism
Carbohydrates source of energy is found in:
- Starch
They are:
- Primary energy source because they are easily broken down into glucose
- Quick energy release. Glucose is rapidly metabolized through glycolysis and cellular respiration, producing ATP
- Storages as glycogen. They are stored in the liver and musscle as glycogen for short-term energy needs
Lipids act as…
energy storage, protection, insulation, lubrication and hormone precursors
Lipids and Carbohydrates hydrophobic or hydrophilic?
Lipids are hydrophobic whereas Carbohydrates are hydrophilic
What are some types of Hormones?
- Insuline: lowers blood sugar levels by promoting glucose uptake into cells
- Glucagon:raises blood sugar levels by stmulating glycogen breakdown in the liver
- Adrenaline (epinephrine): preppares the body for “fight or fight” by increasing heart rate and energy released
- Melatonin: regulates sleep-wake cycles
- Testosterone and Estrogen: control male and female reproductive developmnt and characteristics
- Thyroxine: regulates metabolism and body temperature
- Leptin: controls appetite by signaling the brain to reduce hunger
How enzymes are used in the preparation of milk suitable for individuals who are lactose intolerant?
Lactase enzyme is used to break down the lactose into glucose and galactose through hydrolysis reaction
What is denaturation in enzyme activity?
Its when an enzyme is binding with a substrate and the substrate keeps increasing after the optimal level, the enzyme starts to denaturate, which means its starts to lose its shape and function and to stop working
Explain the role of Carbon dioxide and the increase of temperature in our planet:
Carbon dioxide traps heat in the tamosphere, making the Earth warmer. CO2 is released through burning fuils by cars, factories and cutting trees adds co2 to the air, which are all caused by human activities.
Effect: ice melts, sealeves rise, weather becomesmore extreme
