Lecture 2 - Cell Biology Flashcards
What are atoms?
Atoms are the basic building blocks of matter. Each atom consists of protons, neutrons, and electrons, and represents a chemical element. Atoms cannot be broken down into simpler substances through chemical reactions.
What are atoms made of?
Atoms are made of protons, neutrons, and electrons.
What is the cosmic microwave background radiation?
The cosmic microwave background radiation is the faint light that comes from the first atoms formed in the universe about 13.7 billion years ago. As the universe got bigger, this light stretched out and is now found as microwave radiation that we can detect today.
How far away are the regions that emitted the light from the first atoms?
They are now 46 billion light years away due to the expansion of the universe.
What is the atomic number of an element?
It is the number of protons in an atom’s nucleus.
What are covalent bonds?
Covalent bonds are connections formed when atoms share electrons.
What is a molecule?
A molecule is two or more atoms held together by covalent bonds.
What is an ion?
An ion is an atom or molecule with an overall electrical charge, either positive or negative.
What are salts, and how do they dissolve in water?
Salts are held together by ionic bonds, and they dissolve in water because these bonds break apart in water.
What is the Primordial Soup?
The Primordial Soup is a theory that suggests that early Earth had a mix of simple chemicals and organic molecules—like amino acids and sugars—in its oceans or bodies of water. These compounds were created from natural processes, such as volcanic activity and lightning. Over time, these molecules interacted and combined in ways that eventually led to the formation of the first simple life forms, specifically self-replicating cells. This process is thought to have happened around 4.5 billion years ago, marking a significant step in the development of life on our planet.
When did the first self-replicating cell appear on Earth?
About 3.5 billion years ago, from the “primordial soup.”
What are the main atoms found in cells and their percentages?
59% Hydrogen, 24% Oxygen, 11% Carbon, 4% Nitrogen, 2% other elements (Phosphorous & Sulfur)
- AKA CHNOPS
What are the five main molecules of life found in cells?
Water, Sugar, Fat (Lipid), Nucleotides, and Amino Acids.
What are macromolecules?
They are large molecules formed by the linkage of smaller molecules like sugars and amino acids.
What is the role of ribozymes in early life?
Ribozymes are RNA molecules that help speed up chemical reactions in the body; they assist in making important building blocks like nucleic acids and proteins, which are essential for life.
