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.
What are enzymes?
Enzymes are proteins that speed up chemical reactions in cells. This allows cells to carry out necessary processes more efficiently, like breaking down food or building molecules.
What is the role of ribosomes in the cell?
Ribosomes synthesize proteins by linking amino acids based on the sequence of mRNA.
Why is DNA more important than RNA for storing genetic information?
DNA is more stable and durable, making it better for long-term information storage.
What is a gene?
A gene is a segment of DNA that codes for a specific protein.
What are mitochondria responsible for in eukaryotic cells?
Mitochondria generate ATP, the cell’s main energy source, by breaking down sugars.
What are the major similarities between human and rodent brains?
Rodent brains share similar structures and functions related to cognition, emotions, learning, and memory.
What is neoteny, and why is it significant in humans?
Neoteny refers to the extended growth and development period in humans, leading to prolonged brain plasticity and learning ability.
What is the cell membrane?
The cell membrane is a thin, flexible layer around the cell. It controls what goes in and out, helping the cell stay balanced. It’s made of two layers of fat (lipids) with proteins inside. Some things can pass through, while others can’t, making it selectively permeable. It also helps cells communicate with each other and provides protection.
What is the function of the cell membrane?
The cell membrane, also known as the plasma membrane, controls the movement of substances in and out of the cell. It’s selectively permeable, allowing only certain molecules to pass through.
