1 - Cells Flashcards
<p>Characteristics of living things</p>
<p>Metabolism, Response, Nutrition, Growth, Reproduction, Homeostasis</p>
<p>Cell theory states that</p>
<p>1) All living things are made of cells
2) Cells are the most basic units of life
3) All cells come from pre-existing cells</p>
<p>Exceptions to cell theory</p>
<p>-RBCs
- Bone and muscle cells
- Xylem and skin surface
- Phloem</p>
<p>Compound/Light microscope</p>
<p>x1500, resolution 200+nm, uses light, 2D image in colour, </p>
<p>TEM</p>
<p>Uses electrons, 2D image, x500000, 1 nm resolution, vacuum</p>
<p>SEM</p>
<p>Uses electrons, vacuum, x200000, 2-10 nm resolution, 3D image</p>
<p>Characteristics of prokartyotes</p>
<p>70S ribosomes, Capsule outside cell wall, loops in plasma membrane for anaerobic respiration, no nucleus, DNA in chromatin, Circular DNA as plasmid, no membrane bound organelles</p>
<p>Which organelles are not present in animal cells</p>
<p>Plasmodesmata, chloroplast, cell wall</p>
<p>Components of cell membrane</p>
<p>Phospholipid bilayer, proteins, cholesterol, carbohydrates</p>
<p>Cell membrane is also known as</p>
<p>Fluid mosaic model/plasma membrane</p>
<p>Examples of substance going in and out of the cell membrane</p>
<p>In: Nutrients (oxygen, glucose)
| Out: Nitrogenous wastes, carbon dioxide</p>
<p>Structure of phospholipids (draw if possible)</p>
<p>Phosphate group head, two fatty acid chain tails, all attached to a glycerol.</p>
<p></p>
Polarity of phospholipids?
Head is polar, therefore attracted to other polar molecules and hydrophilic. Tail is non-polar and thus hydrophobic
Functions of membranes in eukaryotes?
- Provide surface for reactions and organelles
- Allow compartmentalisation
- Increase surface area
- Hormone receptors
- Allows transmission/reception of messages
- Isolate harmful substances
2 types of proteins in plasma membrane?
Intrinsic and extrinsic
Width of cell membrane?
7-10 nm
Functions of cholesterol?
- Maintaining rigidity/fluidity of membrane
- Waterproofing
- Prevention of leakage of ions
- Prevents membrane from disintegration
Which factors affect fluidity of cell membrane?
- Cholesterol
- Temperature
- Nature of phospholipids (saturated or not)
- pH
Functions of extrinsic proteins
- Cell adhesion
- Cell signalling
- Cell recognition
Types of transport through membranes
- Passive (simple and facilitated diffusion)
- Active (with ATP)
- Osmosis
- Bulk transport
Characteristics of passive transport
Down conc. gradient, may use channel proteins, no energy required
Characteristics of active transport
Against conc. gradient, requires energy (ATP), involves carrier and pump proteins
Limiting factors of diffusion
- Temperature
- Nature of particles
- Concentration gradient
- Distance to diffuse
- Surface area
What does Fick’s Law state?
(SA x conc. gradient) / distance to diffuse
