Lecture 1 Flashcards
What is life?
Is an emergent property of a particular arrangement of certain molecules.
response to the env
Exchange of material with env
Metabolism
Growth
Reproduction
What is the cell?
Cell is the fundamental unit of living things
Two types of cells
Prokaryotic cell: no true nucleus (ex: bacteria)
Eukaryotic cell: have a true nucleus (ex: algae, we are…)
Unicellular
Each cell carries out all life processes
Multicellular
Made up of many cells with different cells specialized to perform different functions.
What are prokaryotic cells?
Prokaryotic cells can’t be multicellular are mostly monocellular.
Size comparison between plant cell, animal cell and bacterium
Plant cell > animal cell > bacterium
Whats the size of most eukaryotic cells
Most eukaryotic cells are around 10^-4m and 10^-5m (100-10 micrometer).
When does surface to volume ratio increases?
Surface to volume ratio increases the smaller something gets.
Why are cells small?
Cells are small because they require a high surface to volume ratio to exchange materials with their environment.
What is the cell full of? (prokaryotic cell, bacterial)
Cell is full of a semi-fluid aka cytosol.
What is cytosol?
a complex mixture of enzyme and many other molecules in water. Many chemical reactions take place here.
Cytosol pic
What is the plasma membrane/cell membrane?
A boundary between cell and environment. Two parts are non-polar tails (two fatty acids) and one part is a polar head, also called a phospholipid. The polar head will stick to the water molecules with hydrogen bonds. The non-polar tails turn around and face each other, it creates a phospholipid bilayer.
What does the Phospholipid bilayer do?
It controls what comes and goes out of the cell.
What is the Phospholipid bilayer?
a two-layered arrangement of phosphate and lipid molecules that form a cell membrane
Phospholipid bilayer image here
Phospholipid bilayer
What does the non-polar layer do?
The non-polar layer makes it relatively impermeable to polar molecules. When a polar molecule comes close, it gets pulled back (attention: not pushed by the membrane), have trouble crossing it.