A1.1-A1.2 Flashcards
How were the first water molecules formed?
Extremely high temperatures on the earths surface cooled down enough for water to form.
How did the first cells form?
Their thought to have come from the oceans. Because cells need a complex series of chemical reaction to form a solvent is needed. Ocean water provided that solvent.
Water is a solvent that?
- Makes up cytoplasm where all cellular reactions occur.
- Makes up fluid inside all organelles
- Permits transport in and out of the cell
- Essential to blood and other fluid in humans and other organisms
- Provides the medium for oceans, rivers, and lakes
The covalent covalent bonds between oxygen and two hydrogens are what?
Polar covalent
What is a polar covalent bond?
When two atoms have an unequal sharing of electrons
Equally shared electrons create what type of bond?
Non-polar covalent
What is a short lived attraction called?
Ephemeral or hydrogen bonds.
What is surface tension?
When the layer of molecules at the surface of water do not have water molecules above It
What is cohesion?
When molecules of the same type are attracted to each other.
Any substance that dissolves readily in water is called?
Hydrophilic
What are the tubes within a plant called?
The xylem.
Explain how tension works?
Water that evaporates in order to exit the leafs corresponding with cohesion create an area of tension.
What is adhesion?
An attraction between two unlike molecules due to hydrogen bonding
Any substance that does not dissolve readily in water is called?
Hydrophobic
Non-polar molecules (insoluble) found in nature are?
Steroid hormones (oestradiol, testosterone)- can pass through plasma membrane and nuclear membrane because of the hydrophobic similarities.
Proteins that have hydrophobic and hydrophilic sections can imbed there hydrophobic areas into the hydrophobic layers of the membrane while hydrophilic area stay attached but can interact with other substances.
Epidermal cells of leaves secret was coat the leaves and is called the cuticle. It is hydrophobic and acts as a barrier
What are the physical properties of water
- Buoyant force is equal to the weight of water displaced by the object
- Viscosity- Resistance to an object moving through it
List two examples of these properties in nature.
The ringed seal and the black throated loon.
What’s the difference between normal water and deuterium
Normal water contains hydrogen atoms with neutrons and heavy water contains hydrogen atoms that have a neutron
Explain the theory of where water originated from.
The surface of the earth was noting but magma. Then the earth could and asteroids with hydrated minerals struck the earth and released water.
What is the goldilocks zone?
An area with a suitable temperature for water to remain in its liquid form, and sufficient gravity for retaining the water
How many DNA molecules do humans have in each cell in the form of chromosomes ?
46
What is deoxyribonucleic acid (DNA)
A molecule that provides the long term genetic information of organisms on earth. (permanent)