Lecture 3 Flashcards
(20 cards)
What are the three parts of an atom?
- protons
- neutrons
- electrons
Describe the structure of an atom.
protons and neutrons in inside
- electron cloud
What is an isotope?
same proton number, different neutron numbers
- different masses
If an isotope has a half-life of 10 minutes, what proportion of it remains after 1 hour?
1/64
What are the three types of chemical bonds?
ionic bond
covalent bond
hydrogen bonds
What is the difference between a polar and a non-polar covalent bond?
polar: one atom has more pull on the shared electrons
non-polar: equal pull on shared electrons
How do hydrogen bonds form? What kind of chemical bond is necessary for two molecules to share a hydrogen bond?
form between hydrogen of polar molecules
What are the properties of water that make it essential for life?
- cohesion
- temperature regulation
- floating solid state
- polar solvent
What does it mean if a solution has a pH of <7?
acidic
What are the four classes of biological molecules?
carbohydrates
lipids
proteins
nucleic acids
A polysaccharide is what type of biological molecule?
carbohydrates
Which type of biomolecule is not soluble in water?
lipids
What type of biological molecule stores and transmits genetic information?
nucleic acids
What two processes control how DNA encodes proteins?
transcription and translation
Define energy.
ability to perform work
Describe the two laws of thermodynamics as they pertain to biology.
1st: energy can’t be created or destroyed, only moved and changed
2nd: energy changes increases entropy
What is entropy?
randomness/chaos
How do living things cope with the second law of thermodynamics?
can resist flow toward maximum entropy due to energy resupply from sun
Light is what type of energy?
electromagnetic radiation
Describe the difference between fusion and fission.
fusion: making a heavier atom
fission: splitting into smaller atoms
