Biology Quiz #2 Flashcards
1
Q
Particle Model of Matter (4)
A
- All matter is made of particles with varying size &composition
- Particles are constantly in motion (adding & removing energy affects the movement)
- Particles are attracted to one another or bonded together
- Particles have spaces between them (spaced may be occupied by particles of another substance)
2
Q
What are the two methods which molecules move in and out of cells?
A
- Passive Transport 2. Active Transport
3
Q
Passive Transport
A
-Does NOT require additional energy -Includes simple diffusion, osmosis, facilitated diffusion
4
Q
Active Transport
A
Requires energy & transport proteins because it is the movement of molecules against the concentration gradient
5
Q
Simple Diffusion
A
Molecules moving from high concentration to low, until the concentration is equal
- Caused by the collision of particles
- Passive because no extra energy is required
- All molecules diffuse but not at the same rate
6
Q
Concentration gradient
A
The difference in concentration between two points
7
Q
Diffusion Rate is affected by..
A
- Size of molecules (small molecules=faster diffusion)
- Temperature (high temp.= more energy =faster diffusion)
- Concentration (higher conc. = more collosions =faster diffusion
- Medium through which it travels (solids restrict diffusion)
8
Q
Osmosis
A
The diffusion of water across a semipermeable membrane
- relies solely on the concentration gradient
- cells are in extracellular fluid: solution consisting of a solvent and solute
9
Q
Tonicity
A
- Used to determine the direction of diffusion
- ability of an extracellular solution to make water move into or out of a cell by osmosis
10
Q
Hyoptonic
A
Concentration of water greater on the outside
-movement of water into swell (causes cell to swell)
11
Q
Hypertonic
A
Concentration of water is greater on the inside
-movement of water out of the cell (causes cell to shrink)
12
Q
Isotonic
A
Concentration equal both in & out of cell
-water moves into & out of the cell at same rate
13
Q
Crenation
A
-process of cell losing water and shrinking
14
Q
Cytolysis
A
Swelling & bursting of cell
15
Q
Osmoregulation
A
The control of water balance
16
Q
Turgor Pressure
A
Plants rely on osmosis to regulate the water pressure exerted on the inside of their cell walls
-no turgor pressure = plants wilt
17
Q
Plasmolysis
A
Occurs when cell membrane of plant cell shrinks away from cell wall due to being placed in a hypotonic environment
18
Q
Deplasmolysis
A
Re-hydration of plant cell due to being placed in a hypotonic environment
19
Q
Water Potential (4+formula)
A
- Water uptake/loss must be balanced
- Water moves by osmosis
- Cell walls add physical pressure which affects osmosis
- Water potential (Ψ) takes both solute and physical pressure
- Formula: Ψ = Ψs + Ψp
20
Q
Adding solute does what to the water potential?
A
Adding solute lowers water potential because there is less free water molecules (less capacity to do work) -the Ψs is negative
21
Q
Facilitated Diffusion (5)
A
Only matter that is soluble in lipids can pass through the lipid bilayer by simple diffusion
- water soluble particles use the protein channels to move across the membrane by diffusion
- small molecules & ions pass through the pores created by the channel proteins
- big molecules are helped across the membrane by the transport proteins
- molecules are moving down the concentration gradient, therefore no extra energy is needed
22
Q
Membrane Technologies (6)
A
- industrial use of synthesis to mimic actions of membrane
- study of receptor proteins that bind with specific molecules to bring them into the cell by endocytosis
- useful in the study of HIV & cancer
- focus on recognition of receptor proteins to prevent virus from getting in
- develop drugs that target the unique proteins of cancer
- development of drugs that stimulate the immune system to detect & destroy cancer cells
23
Q
Synthetic Membrane Technologies (3)
A
- liposomes are fluid-filled sacs surrounded by a phospholipid bilayer identical to the membrane in human cells
- used to deliver drugs to infected tissues in a controlled delivery system
- inside holds water-soluble medicine while the bilayer holds fat-soluble medicine
24
Q
Advantages to Synthetic Membrane Technologies
A
- Liposomes stay in blood for longer than medication on it’s own
- Delivers treatment to target cells only (no harm to other cells)
- Used in gene therapy to inject DNA into cancer cells to kill them
25
Dialysis
- rid body of toxins, wastes, & excess fluids
- two types available to people with kidney failure (hemodialysis & peritoneal dialysis)
- both based on the principle of diffusion & osmosis
26
Hemodialysis ("hemo" = bloodcells)
1. must be performed in hospital
2. blood removed from body, cleansed, returned to body
27
Peritoneal Dialysis
1. soft catheter inserted into abdominal cavity
2. sterile dialysate fluid pumped into cavity
3. toxins move down the concentration gradient into the fluid which is then removed from body
28
Surface Area to Volume Ratio (sa/v)
- amount of membrane (sa) around a cell in relation to the size of cell (volume) determines how many molecules will pass in and out of cell
- cells divide to maintain a high surface area to volume ratio
- cell grows larger = sa/v ratio drops til cell is not efficient = growth slows = cell divides
- organisms have specialized structures to help increase overall SA/V ratio
29
Single-Celled Organisms
- Can live individually or in colonies
- quite small, microscopic
- entire cell performs all functions to maintain life
30
Tissues
groups of cells performing the same function eg. red blood cells
31
Organ
groups of tissues contributing to the same function eg. heart
32
System
group of organs contributing to the same function eg. circulatory system
33
Specialization
- Once a single-celled organism or colony reaches certain size, it requires a multi-cellular level of organization
- This need resulted in the development of specialization of cells, tissues, & systems
- This "division of labour" in larger organisms allows greater efficiency in life processes therefore increasing survival
34
Shoot System (plant)
- everything above ground
- includes fruit, stem, leaves, buds, tubers even though they under ground
35
Root System
- everything underground
- includes aerial roots even though they above ground
36
Dermal Tissue (Epidermis) (6)
- outer layer of cells that covers all non-woody plants
- one cell layer thick
- responsible for the exchange of matter & goes into and out of the plant
- in woody plants the epidermis of the stem is replaced by cork bark
- dermal tissue of the leaves & stem involved in gas exchange
- protects the plant from disease
37
Ground Tissue
- found as layer beneath epidermis
- provides strength & support (stem)
- involved in food & water storage (roots) -site of photosynthesis (leaves)
- air spaces between cells allow gases to diffuse
38
Vascular Tissue
- responsible for transport of materials
- contain pholem & xylem tissues that transport water, dissolved minerals, sugars
39
Xylem
- moves water & dissolved minerals from the roots up
- made of tracheids & vessels (dead cells)
40
Pholem
- transports sucrose & other dissolved sugars from leaves to other parts
- made of sieve tubes & companion cells (living)
41
Sieve tube cells
-cylindrical cells lacking nuclei &with perforated sides & end walls that allows movement of pholem sap between cells
42
Companion Cells
-type of small pholem cells adjacent to sieve tubes that appear to control sugar transport in the pholem
43
Vascular Cells "bundle of straws"
- strand of xylem, pholem, & associated tissue in plant
- veins in leaves are extensions of vascular bundles of the stem
44
Meristems
- growth region of plant with tissue in which cells divide by mitosis
- apical (vertical growth) & lateral (horizontal)
45
Cuticle
- waxy, non-cellular waterproof coating that covers a plant's leaves & stems
- resists attack from micro-organisms
- helps reduce water loss
46
Root Hairs
-absorb water & minerals
47
Guard Cells
-swell & contract to control gas exchange through a stomata in leaf (controls size of stomata)
48
Stomata
-pores that allow gases to pass through epidermis of lead (site of water loss & gas exchange)
49
Photosynthesis
- plants contain chloroplasts that contain chloropyll
- found in ground tissues of leaves (mainly) & somtimes in stems
- light energy is absorbed by the chlorophyll & converted to chemical energy & stored in bonds of the glucose molcules
- cannot take place in dark
- water + carbon dioxide --\> glucose = oxygen (6 H20 + 6 CO2 --\> C6H12O6 + 6O2)
50
Cellular Respiration
- provides the energy of the cell's life processes
- bonds are broken & new compounds formed releasing energy
- takes place in the mitochondria
- takes place all the time in both plants & animals
- glucose + oxygen --\> water + carbon dioxide (C6H12O6 + 6O2 --\> 6H2O + 6 CO2)
51
Leaf Tissues & Gas Exchange
- guard cells form tiny pores called stomata that allows gas exchange to happen easily -carbon dioxide and oxygen can enter &leave by diffusion
- most stomata re found in lower epidermis
- guard cells swell up to open the stomata
- potassium ions move in by active transport, & water follows by osmosis
52
Transpiration
- process of water vapour leaving the leaf through the stomata
- controlled by guard cells
- number & appearance of stomata depends on the envir. conditions
eg. hot, dry -\> very few stomata humid -\> many stomata
53
Spongy Mesophyll Tissue (4)
- irregularly shaped, less rigid cells
- between the palisade tissue cells & lower epidermis
- moves oxygen towards stomata for expulsion -moves carbon dioxide from the air towards the palisade cells
54
Transport in Plants
-osmosis, diffusion, active transport, & transpiration result in the movement of materials through plants
55
Cohesion
- the attraction of water molecules to other water molecules
- due to water having slight positive end & a slight negative end
- causes water molecules to hold together contributing to high surface tension
56
Adhesion
-the attraction of water molecules to molecules of unlike substances
57
Root Pressure (5 steps + 4)
Cell around the xylem swells, squishing the xylem, and pushing the fluids out
1. ) Dissolved minerals present in cells of roots as a result of active transport, thus producing a higher solute concentration inside the cell
2. ) Through osmosis, water is drawn into the cells, creating positive pressure that forces fluid up the xylem
3. ) Water is forced from a higher pressure in the roots, toward the lower pressure in the leaves
4. ) The evaporation of water through the stomata in transpiration created tension (main cause of water movement
5. ) As each water molecule evaporates, it creates a pull on the adjacent water molecules pulling them up the xylem vessels to the leaves
- most water is lost though the stomata (evaporation)
- transpiration pull maintained to continue drawing water up stem
- high temp. = high rate of evaporation = movement through xylem rapid
- rest of water used to produce sugars
58
Tonicity (plant)
- as water enters the plant cells by osmosis, the cell is turgid
- is better for cells to be in hypotonic envir.
59
Turgidity
-Allows plant to hold itself up so it can get sunlight for photosynthesis
60
Control Systems
Stimulus = change in environ. casues reaction in an organism
eg. loud noise, bright light
- both plants & animals respond to stimuli
- "tropism" refers to the movement of a plant in response to a stimuli
61
Phototropism
-plant growth in response to light -plant tip detects stimuli & sends chemical to area of elongation
62
Auxin
A hormone that promotes cell growth or elongation of cells facing away from light, causing leaf or stem to bend toward light
63
Positive Phototropism
Growth towards light source eg. stem, flowers
64
Negative Phototropism
Growth away from light source eg. roots
65
Gravitropism (geotropism)
- plant grown in response to gravity
- plants depend on heavy starch particles in specialized cells as indicators of gravity
- starch grains shift & settle due to gravity
66
Positive Gravitropism
Growth towards gravitational pull eg. roots
67
Negative Gravitropism
Growth away from gravitational pull eg. stem
68
Other Control Mechanisms
- temp., chemicals, water
- tendrils respond to touch (eg. peas)
- flowering is often response to length of darkness that plant is exposed to (eg. christmas cactus)
69
Endocytosis (type of active transport)
Cells use it to bring particles in
1. Cell membrane engulfs a molecules
2. Pinches off to form a transport vesicle around it
3. Cells use the contents when needed
- requires enegery in the form of ATP
70
Exocytosis
71
Protein Pump
- small particles transferred
- carrier protein in membrane carriers particle to other side
- all cells have voltages across their plasma membrane (membrane potential)
- inside the cell is negative compared to outside
- ions move the electrochemical gradient which takes into consideration graiendt & charge gradient
