L02 Flashcards
What person advanced the field of neuroscience the most?
Charles Darwin. All animals in the world (all cells in the world) have a lot in common because they all are descendants of a common ancestor
Cells are made up of atoms: _____, ______, and _____.
protons, neutrons, electrons
Most (>99.9%) of the atoms in the universe are _____ or _____.
hydrogen, helium
How old is the oldest light we can detect?
13.7 billion years old
How far is the oldest light we can detect now because of the expansion of the universe?
46 billion years away
What is ordinary matter made of?
Elements on the periodic table
How many elements are there in the periodic table?
118 elements, but only the first 94 occur naturally on Earth
The air we breathe is largely (99%) just __ and __.
N2 and O2
What is an atom?
A chemical element
When atoms bond together, they form a _____.
molecule
What does a chemical reaction refer to?
A molecule being formed, broken, or modified in some way. ex: change in the position of electrons in the molecule
What is a molecule or single atom that has an electric charge and often breaks apart in water?
An ion
What are molecules held together by ionic bonds called?
Salts
The likelihood of a chemical reaction depends on many factors. Name one.
Temperature
When was Planet earth formed?
4.5 billion years ago
What happened sometime in the first billion years of Planet Earth?
One self-replicating cellular entity emerged out of the “primordial soup”
What are the main elements of cells (life on Earth) and their percentages?
-59% Hydrogen
-24% Oxygen
-11% Carbon
-4% Nitrogen
-2% Others (phosphorus, sulfur, …)
What does CHNOPS stand for?
Carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.
They represent the six most important chemical elements whose covalent combinations make up most biological molecules on Earth.
What are some examples of molecules we can find in cells?
Water, sugar, lipid, nucleic acid, amino acid
What molecules formed naturally on Earth prior to the first lifeform and have been found on asteroids?
Water, sugar, lipid, nucleic acid, amino acid
What are cells made up of besides water (70% of total cell mass)?
-15% Sugars (strings of sugar molecules are called carbohydrates)
-10% Lipids (cell membranes and vesicles are made of lipids)
-15% Nucleic acids
-50% Amino acids
-10% Other organic (CHNOPS) molecules
What does RNA mean?
Ribonucleic acid
Some RNA strands are _____.
self-replicating
What are phospholipids?
Strands of fat (lipid) with a phosphate cap
Lipids prefer the company of other _____, while phosphate groups prefect to interact with _____.
lipids, water
What do phospholipids form if left undisturbed?
Bilayer sheets
What do phospholipids form when shaken?
Micelles
What will micelles do under certain conditions?
Micelles will explode and reform as liposomes