Cell and its constituents Flashcards
What are the two major cell types?
Prokaryote
Eukaryote
What is a prokaryote?
Bacteria
No cell compartments
Unicellular
What are the components of a prokaryote?
Cell wall Flagella Cell membrane Ribosomes Plasmid Cytoplasm
What is a prokaryote cell wall made of?
Peptidoglycan layer made of polysaccharides and polypeptides
What is the purpose of a cell wall?
Provide support to the cell from internal pressure
What is a eukaryote?
Animal and plant cells
They are complex cells with organelles
What are the organelles in a eukaryotic cell?
Cell membrane Nucleus Endoplasmic reticulum Ribosomes Golgi apparatus Mitochondria Lysosomes Cytoplasm
What are the components of the cell membrane?
Phospholipid bilayer
Channel/carrier proteins
cholesterol
glycoproteins/globular proteins
What are the parts of a lipid?
Polar head
Non-polar tail
What are micelles?
Collection of lipids with the hydrophobic tails pointing in and the hydrophilic head pointing outwards
What is the purpose of a phospholipid bilayer?
To prevent polar molecules from passing through the membrane
What are the types of life forces involved in biological systems?
covalent bonds electrostatic interactions hydrogen bond hydrophobic interactions solvent considerations
What is a covalent bond?
Two atoms sharing electrons
What are some characteristics of covalent bonds?
Strong bonds
determine the structure of biomolecules
What is ionic interactions?
interaction between two ions
They can be strong
What are dipole-dipole interactions?
Interaction between two dipoles or an ion and a dipole
Dipoles arise from differences in electronegativity
What are dispersion forces?
Interaction between temporary dipoles
Non-polar molecules can occasionally have uneven electron distribution
What is a hydrogen bond?
Interaction between a hydrogen atom bonded to N,O, F and N, O, F atoms
What is the length of a hydrogen bond?
2.5Å
What happens to hydrogen bonds when they become longer than 2.5Å?
They become dipole-dipole interactions
What are hydrophobic interactions?
interactions between non-polar molecules
What are hydrophobic interactions based on?
Entropy
ΔG = ΔH - TΔS
What is the driving force for hydrophobic interactions?
Increased entropy
More disorder
What type of bonds are in polypeptides?
Covalent bonds
What type of bonds are in DNA?
Covalent bonds
What type of bonds are there between enzymes and small molecules?
Hydrogen bonds
ionic bonds
What bonds does water weaken?
ionic
dipole
hydrogen
What is the importance of weak interactions?
weak by themselves but strong together which aids in protein folding
