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
Types of endicytosis
- Phagocytosis (cell eating)
- Pinocytosis (cell drinking)
How are solute potential and water potential related?
They are inversely proportional
3 types of solutions?
- Isotonic: Water potential is equal
- Hypotonic: Outside of cell has more water potential
- Hypertonic: Inside of cell has more water potential
Magnification formula?
Image size / Actual size
Which molecules are non-polar?
Lipids
4 stages of mitosis
- Prophase
- Metaphase
- Anaphase
- Telophase
Stages of cell cycle
- G1: Growth
- S: DNA Replication
- G2: More growth
- Mitosis: Karyokinesis
- Cytokenesis
What occurs in Prophase?
- Nucleolus degrades
- Chromosomes condense (supercoiling)
- Mitotic spindle forms
- Centriole duplicates
- Nuclear envelope degrades
What occurs during Metapahse?
- Chromosomes align in a line
- Spindle fibres attach to centromeres at kinetochores
What occurs during Anaphase?
- Chromosomes pulled towards poles of cell by centrioles
- Microtubules attached to cells get shorter and contract
What occurs during Telopahse?
- Mitotic spindle broken down
- Two nuclei form
- Chromosomes decondense and form chromatin
Cytokinesis in animal and plant cells?
- Animal: Cleavage furrow forms and cells split in two
- Plant: Cell plate forms in middle of cell
What 4 factors are needed for spontaneous synthesis of cells?
- Non-living synthesis of organic molecules
- Assembly of organic molecules into polymers
- Origin of self-replicating molecule with inheritance
- Packaging of these molecules into membranes
How was it found that organic molecules could be synthesized in ancient Earth?
Urey-Miller Experiment: Simulated ancient Earth environment and lightning. Organic molecules (amino acids) were created.
3 places cells may have originally existed?
- Hydrothemal vents
- Volcanoes
- Space (Panspermia theory)
Comet theory for origin of cells?
Comets have organic molecules on them. They may have originally carried them to Earth, as there were many comets millions of years ago. The impact could have polymerized the amino acids present.
Properties of water?
- Universal solvent
- High specific heat capacity
- Polar
- Less dense when solid
- Cohesive and adhesive
