A - unit And Diversity (A1.1, A1.2) Flashcards
What are the physical and chemical properties of water that make it essential for life?
Water is polar
Water is less dense than solid then a liquid
Water has cohesive and adhesive properties
What is adhesion?
Different molecules attract each other
What is cohesion?
Like molecules attract each other
Water is a solvent. what does it do?
Water helps molecular organisms transport molecules around a body and acts as the medium in which chemical reactions occur
Water is a metabolite. What does it do?
Chemical reactions take place in cells. These reactions are called metabolism. Water is involved in photosynthesis and aerobic respiration.
Water is temperature buffer what does this help with?
Water helps to buffer temperature changes in the cells because of its high specific heat capacity
Water maintains, biological structures. Give some examples.
Water contributes to the formation of cell membranes
Water impacts the folding of proteins
Water surrounds DNA to support the double helix
What do protons, neutrons and electrons carry? (charge.)
Protons carry a positive charge
Neutrons carry no net charge
Electrons have a negative charge
What is an atom when the protons and electrons are equal?
Atoms are electrically neutral if they have an equal number of protons and electrons
Why are electrons in an atom attracted to protons in the nucleus?
The nucleus has an electromagnetic force in which positive charge attracts negative charge
What is atomic bonding?
Electrons can be transferred to another atom or is shared between atoms
Name the four types of bonds
Nonpolar covalent bond
Polar covalent bond
Ionic bond
Hydrogen bond
What is nonpolar and polar covalent bond
Nonpolar share electrons equally
Polar share electrons unequally
What does ionic bonding
The attraction between positively charged ion and negatively charged ion
What is a hydrogen bond?
An attraction between two polar molecules
What is a polar molecule?
A molecule which one end of the molecule is slightly positive while the other end is slightly negative
What is the water structure?
A water molecule consists of two hydrogen and one oxygen atom H2O
What happens within a water molecule?
Electrons are shared through polar covalent bonding between the atoms
Why is the water molecule polar?
Because oxygen atoms have more protons, which attracts the shared electrons more of the time, creating an unequal distribution of charge
+ hydrogen
- oxygen