AICE Marine A level chapters 6-7

what does a plant cell include?

* cell membrane
* nucleus
* rough + smooth ER
* Ribosomes
* golgi body
* mitochondria
* chloroplasts
* cell wall
* large permanent vacuole

label plant cell

function of cell membrane

* boundary of a cell with its exterior
* controls the movement of substances in and out of the cell
* receives instructions from other cells

function of nucleus

* contains genetic material

function of rough ER

* majority of the ER
* has ribosomes on surface
* folds and packages proteins
* proteins are “budded off” in a vesicle and moved to Golgi

function of smooth ER

* less abundant
* no ribosomes
* synthesizes steroid hormones
* large amounts found in testicles and ovaries

function of ribosomes

protein synthesis

function of golgi body

* chemical modification of proteins, such as adding carbohydrates
* produces substances needed for plant cell wall synthesis
* produces lysosomes

function of mitochondria

* produce ATP by aerobic respiration in animals and plants
* cells with high energy requirements have large amounts of mitochondria

function of chloroplast

* carry out photosynthesis

label chloroplast

Stroma (in chloroplast)

* where light independent stage occurs

Thylakoid membrane (in chloroplast)

where light dependent stage occurs

Grana (in chloroplast)

stacked thylakoid membranes containing photosynthetic pigments; trap light energy

function of cell wall

* strength and support for whole plants
* preventing cells from bursting due to inflow of water
* only in plant cells
* made of cellulose

function of large permanent vacuole

* in plant cells
* stores pigments, water, and waste products

phospholipids

* fatty acid tail is uncharged (does not want water to enter)
* phosphate head is charged and hydrophilic (wants to enter water and dissolves in water)

carrier proteins

* possess specific binding site to which substances bind and change shape as the substance is moved across the membrane

channel proteins

* a pore through which substances will pass through

fluid mosaic model labeled

active transport

uses energy to pass molecules through carrier proteins

passive transport

* diffusion
* no additional energy input (small and non-polar like O2 and CO2 diffuse through phospholipid bilayer between fatty acid tails)

labeled animal cell

how to calculate magnification of an image

* measure the length of the image with a ruler
* ensure to have the same units for the image length and actual length
* use the formula for magnification by dividing the image length by the actual length

diffusion

the movement of molecules from high to low concentration (passive process = no additional input of energy)

facilitated diffusion

movement of molecules from high to low concentration through carrier or channel proteins

osmosis

diffusion of water (from higher to lower water potential)

active transport

* using energy (ATP) to move molecules across the cell membrane
* carrier proteins bind molecules to one side of membrane
* atp binds to carrier protein and is broken down to ADP and phosphate
* releases energy
* energy is used to change shape of protein to move the molecule across the membrane
* returns to original shape

water potential

potential energy of water in a solution compared to pure water; water will move by osmosis from high to low water potential

* the more water molecules, the higher the water potential
* if a solute such as salt is dissolved in water, the proportion of water molecules in the solution decreases water potential

hypertonic

solution has greater concentration of solutes

* lower water potential than the cells/body fluids of an organism

isotonic

solution has greater concentration of solutes

* lower water potential than the cells/ body fluids of organism

hypotonic

solution has lower solute concentration

* higher water potential than cells/body fluids of organism

smaller organisms/cells have a larger or smaller SA:volume ratio?

larger

Larger SA:Volume ratio =

faster rate of diffusion

why do larger organisms need gills or lungs

for diffusion

increased surface area (like tentacles or coral polyps) =

increased area through which gases can diffuse

gills

* gill arches hold gill filaments
* gill filaments have a number of lamellae
* lamellae increase the gas exchange surface area

Gill hyperplasia

* Shortening, rounding, and fusion of gill lamellae
* increases mucus production
* reduces surface area for gas exchange

circulatory system in a typical fish

1. blood passes through muscles and other body tissues and releases O2→picks up Co2
2. blood pumped back to the heart (through veins)
3. blood pumped from heart to gills (through arteries)
4. blood passes through gills (capillaries) + releases CO2 and picks up O2
5. Blood leaves gills (in arteries) and travels to muscles and other body tissues
6. to deliver O2 and remove CO2

what organisms use simple diffusion

small animals and/or animals with thin/few tissue layers

* coral polyps

pumped ventilation

* demersal and slow swimming fishes (ex. grouper)


1. Open mouth, close operculum, creates a low pressure in the buccal cavity, draws water in
2. close mouth, open opercula, increases pressure in the buccal cavity, pushes water out through the gills (diffuse O2 in and CO2 out)

ram ventilation

* pelagic fishes (constant swimmers; have higher o2 demand) ex. tuna
* swim continuously, with mouth open, so water constantly flows in through the mouth and over the gills to diffuse O2 in and CO2 out

why do marine organisms need to regulate their water content and ion content

if they live in an environment with high salinity and low water potential

osmoconformer

* organism with the same internal solute concentration/water potential as surrounding water
* ex. mussels
* when salinity changes, mussels close shells to prevent seawater coming into contact with body tissue
* can increase and decrease solute concentrations of their cells if external salinity changes

osmoregulator

* organism that maintains internal solute concentration (body fluids)
* Ex. salmon, tuna, bull shark
* salmon migrate from freshwater to the ocean and maintain their internal solute concentration
* tuna live off shore their entire lives, where salinity doesn’t change
* bull sharks (juveniles) migrate from the ocean into freshwater rivers

euryhaline

* organisms that can tolerate a WIDE range of salinities
* ex. salmon, bull sharks, and mussels

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stenohaline

* organisms that can tolerate only a NARROW range of salinities
* ex. tuna

Osmoregulation characteristics in marine fishes

* surrounding water typically has higher salinity than their cells and body fluids
* constantly drink seawater to replace water lost by osmosis
* Sodium and chlorine ions are actively secreted by the gills. Specialized cells on the gill filaments have protein “pumps” that pump ions into the water; uses ATP
* magnesium and sulfate ions are actively secreted by the kidney into urine
* reabsorption of water by the kidney produces a low volume of very concentrated urine

osmoregulation characteristics in freshwater fishes

* surrounding water has lower salinity and higher water potential than their cells and body fluids
* drink small amounts of water
* gills actively pump sodium and chloride ions into blood and body fluid. specialized cells have protein pumps that actively pump the ions from the external water to the internal body fluids; uses ATP
* produce large amounts of very dilute urine

electromagnetic spectrum

from left to right:

* gamma rays
* x-rays
* ultraviolet light
* visible light
* infrared
* radio waves

light wavelength

the wavelength/visible color of light in nm

light intensity

measure of strength or brightness of light

light penetration

depth at which light can penetrate through water

red light

* penetrates into the most shallow waters - down to 10 m
* as it is absorbed by the surface water
* longest wavelength (620-720nm)

blue light

* penetrates the deepest - down to 200 m
* short wavelength

green light

* penetrates depths deeper than red, but shallower than blue

photosynthesis number equation

6co2 + 6H20 → C6H12O6 + 6O2

light dependent stage

* takes place in grana of the thylakoid membranes
* trap light energy and transform into chemical energy used to produce glucose
* grana contain primary and accessory pigments embedded in their membranes in clusters called photosystems
* when chlorophyll a (primary pigment) absorbs light energy it undergoes photoactivation
* the molecule loses an electron; it is oxidised (losing electrons: oxidation, gaining electrons: reduction)
* b/c the electron loss was due to the trapping of light (photooxidation)

summary of light-dependent stage

* function : harvest light energy and convert to chemical energy
* energy is given to 2 molecules, ATP and reduced NADP
* photolysis of water provides electrons to replace those lost by oxidized chlorophyll a
* oxygen is released as a byproduct of photolysis

light-independent stage

* 2nd stage of photosynthesis
* the energy (ATP and reduced NADP) that has been harvested in the light dependent stage is used to make glucose by carbon dioxide fixation
* takes place in the stroma of the chloroplast
* calvin cycle makes glucose
* carbon containing molecules are converted through a range of different forms

calvin cycle

* carbon dioxide is combined with RuBP by enzyme rubisco
* Joining carbon dioxide and RuBP makes a sugar with 6 carbon atoms which breaks into GP
* GP is converted into a diff sugar called TP which produces glucose from ATP and NADPH
* some of the TP is used to make glucose while the rest is used to make new sugar called RuP
* RuP is given another phosphate by more ATP to make RuBP. The RuBP can then repeat the calvin cycle with fresh carbon dioxide

light independent stage summarized

* uses the energy from ATP and reduced NADP that were produced in the light dependent stage
* enzyme rubisco combines carbon dioxide with RuBP
* it fixes carbon dioxide and makes glucose
* energy from light ends up in the glucose

chloroplast pigments

* absorbs blue and red
* organisms that are green live in the shallowest depths (to absorb red light)
* carotenoids absorb blue
* organisms that are yellow/brown/orange live deeper
* fucoxanthin absorbs blue and green
* phycocyanin (blue-green) absorbs orange, yellow and green
* Phycoerythrin absorbs blue and green

green algae and seagrass live in

shallowest water

blue-green (contains phycocyanin) bacteria live in

deeper water

brown/yellow/orange algae (kelp, dinoflagellates, etc) live

deeper than green

red algae lives

in the deepest, but still shallow water bc they need sun for photosynthesis

red and brown algae live

at deeper depths

why do pigments live at varying depths

based on their absorption spectra to REDUCE COMPETITION

effect of light intensity on rate of photosynthesis

increases then stabilizes bc another factor becomes limited

effect of carbon dioxide concentration on rate of photosynthesis

increases then stabilizes bc another factor becomes limiting

effect of temperature on the rate of photosynthesis

increases then falls bc enzymes denature

chemosynthesis

the fixation of carbon using the chemical energy of dissolved substances

chemosynthesis formula

12H2S + 6CO2 → C6H12O6 + 6H2O + 12S

hydrogen sulfide + carbon dioxide → glucose + water + sulfur

endoriftia and riftia

* mutualism
* endoriftia lives in riftia’s trophosome
* using their plume (external gills) riftia takes in H2S for Endoriftia to chemosynthesize
* Endoriftia produce glucose and other organic molecules
* Endoriftia get constant supply of H2S for chemosynthesis

aerobic respiration

* energy is released from glucose by oxidation, producing carbon dioxide and water as waste products
* aerobic=uses oxygen
* energy released is ATP
* begins in cytoplasm, continues in mitochondria
* 1 molecule of glucose produces up to 38 molecules of ATP

anaerobic respiration

* without oxygen
* incomplete combustion of glucose
* 1 glucose molecule generates only 2 molecules of ATP
* occurs in cytoplasm

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