Life at the Cellular Level Flashcards
Difference between passive and facilitated transport?
- Both require conc. gradients
- Facilitated needs carrier molecules
Define endocytosis
Invagination of the cell membrane to take in extracellular materials
Define exocytosis
- Vesicle produced
- Internally made proteins put inside vesicle
- Vesicle fuses with cell membrane and constituents move out
Role of an occluding/tight junction
- Waterproof
- Seals gap in-between cells
- Stops absorbed nutrients from returning in-between the cells
Role of adherens junction?
- Uses actin
- Connects two cells to each other to allow uniform movement
Role of desmosomes
- Uses intermediate filaments
- Connects two cells to each other to allow uniform movement and structure
Which of the two adhering junctions is stronger?
Desmosomes
Role of gap junctions
Allow communication between cells
What messenger molecules move through gap junctions
Small, water soluble
What is the name of the protein that makes the pores of the mitochondria?
Porin
What shape is mitochondrial DNA found?
Circular
3 things found in the nucleus?
- DNA
- Nucleoproteins
- RNA
Where is rRNA synthesised?
Nucleolus
Role of the rough ER?
- Protein modification and transport
Role of the golgi apparatus?
- Protein modification and packaging of complete polypeptides into vesicles
- Can synthesise complex polysaccharides
What is the role of the smooth ER?
Breaks down - Drugs - Glycogen Synthesises - Lipids
Role of lysosomes?
- Contain digestive enzymes so they don’t digest the cell
Main functions of the cytoskeleton?
- Structure
- Motility
- Organisation of organelles
- Involved in cytoplasmic streaming
3 parts of the cytoskeleton?
- Actin
- Intermediate filaments
- Microtubules
What are intermediate filaments made of?
- Fibrous proteins
What are microtubules made of?
Tubulin
Name the 10 most common elements found in the body
- H
- O
- C
- N
- Ca
- Na
- Cl
- P
- S
- K
What do S groups allow to form
Disulphide bridges
What is configuration?
The FIXED arrangement of atoms in a molecule, either cis of trans
What are the 5 reactions that occur in the body?
- Breaking and forming C-C bonds
- REDOX
- Internal rearrangements
- Group transfers
- Condensation/hydrolysis
What is conformation?
- The PRECISE arrangement of atoms in a molecule with FREE ROTATION
What is the role of the peroxisome?
- Break down of FA’s with chains longer than 22 C’s
- Breaking down hydrogen peroxide
