Module 1/ The cell: the unit of life Flashcards
What is life?
So life is basically anything that differentiates us from, inanimate objects, like clouds or rocks and things like that.
What are the 7 properties of life and explain them?
- Cellular organization:
- Energy and metabolism:
- Reproduction (bacteria can reproduce)
- Heredity and evolution
- Growth and development (development of an embryo)
- Regulation and homeostasis (keep things in your body stable)
- Response to stimuli:
What is the cell theory?
- Basic structural, functional, and biological unit of organisms
- Smallest unit of life
- All cells are derived from previous cells
- All organisms are made up of cells
What are viruses?
-An infectious particle that can replicate inside the cell, but can not replicate outside the cell.
-Can infect from person to person (RNA or DNA genome +capsid made of protein)
-It is surrounded by nucleic acid
-Some have a membrane (SARS-COV2)
What are prions?
-Are not bacteria nor viruses, they are infectious proteins
-They are proteins that have not been folded correctively, they are misfolded
-If it enters the cell it can turn the other proteins to be misfolded
What are viroids?
-Are made of a single strand of circular RNA
-They were only found to harming plants. Now found in humans (Hepatitis D)
-They do not make proteins but they can make copies of them inside plant cells and spread to other plants.
What is life on Earth with the use of carbon?
-They are highly abundant on earth and in the atmosphere
-Small molecular weight and size
-Can bind to 4 other atoms to form reactive and stable organic molecules
-Can bind to other carbon atoms: polymerization (monomers combine together to make a chain polymer)
Which molecules constitute the majority of biological molecules?
-Carbon (C)
-Oxygen (O)
-Hydrogen (H)
-Nitrogen (N)
What and when was the first cell discovered?
The prokaryotes was the first cell discovered 3.5 billion years ago.
How do we know know the origin of a cell?
We hypothesize and see any evidence on Earth.
In Early atmosphere:
-Organic molecules were coming from the atmosphere and brining bit of energy through lightning and re-arrange molecules together to form molecules
Deep-sea vents:
-Deep in the ocean you have a lot of energy, you have a lot of thermal vents. Those are hot springs at the bottom of the ocean. Deep down their was a lot of organic molecules, its possible to have the formation of complex molecules that together can have a formation to the first living cells.
Clay:
- On earth we also find clay. It is a good catalyst it can bind a lot of nucleic acid and line them up right next to each other.
-The first evidence is the Stromatolites from 3,500 million years ago. They are not living organism, but they are fossils.
What are the functions of a cell?
1.Contain and transmit genetic material
- Conversion of energy (catabolism)
- Absorption of energy (anabolism)
- Structure and support (cytoskeleton)
- Response to certain stimuli (cell signaling)
- Barrier and defense mechanism (plasma membrane)
- Transport of molecules (osmoregulation, gas exchange)
- Reproduction (gametes)
What is the central dogma?
Central dogma is a theory in which it states that you can only transfer from nucleic acid to nucleic acid or nucleic acid to protein. However, you can not go from protein to protein or protein to nucleic acid because it is not possible.
What was the previous theory before the central dogma?
One gene=One protein
Before we thought it was a gene that was coding for a protein, and that’s it.
What did James Watson later propose?
-RNA molecules can be transferred into a DNA.
-That DNA can replicate itself
When was eukaryotes discovered?
1.8 billion years ago
