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Science B4
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movement
moving
respiring
a series of chemical reactions that release energy by breaking down large food molecules in all living cells
sensitivity
detecting changes in the surroundings (such as light levels)
growth
growing
reproduction
making a new generation of a species
excretion
getting rid of waste (e.g. carbon dioxide from respiration)
nutrition
taking food and using it as a supply of energy
photosynthesis
a series of chemical reactions that use energy from sunlight to build large food molecules in plant cells and some microorganisms (eg phytoplankton)
enzymes
proteins that speed up chemical reactions
cells make enzymes
according to the instructions carried in genes
molecules
have to be the correct shape to fit into the active site of the enzyme (the lock and key model)
enzymes need a specific constant temperature
to work at their optimum
enzymes permanently
denature if the temperature is too high
increased rates of reaction
as temperature increases
at a specific pH
enzyme works at its optimum
a pH too high or low
enzyme denatures
equation of photosynthesis
carbon dioxide + water-> light energy -> glucose + oxygen
balanced equation of photosynthesis
6CO2 + 6H2O -> light energy-> C6H12O6 + 6O2
First step of photosynthesis
light energy absorbed by the green chemical chlorophyll
Second step of photosynthesis
energy is used to bring about the reaction between carbon dioxide and water to produce glucose (a sugar)
Third step of photosynthesis
oxygen is produced as a waste product
chloroplasts
contain chlorophyll and the enzymes for the reactions in photosynthesis
cell membrane
allows gases and water to pass in and out of the cell freely while presenting a barrier to other chemicals
nucleus
contains DNA which carries the genetic code for making enzymes and other proteins used in the chemical reactions of photosynthesis
cytoplasm
where the enzymes and other proteins are made
minerals taken up by plant roots are used to
make some chemicals needed by cells including nitrogen from nitrates to make proteins
diffusion
the passive overall movement of molecules from a region of higher concentration to a region of lower concentration
movement of oxygen and carbon dioxide in and out of leaves during photosynthesis occurs by
diffusion
osmosis (a specific case of diffusion)
the overall movement of water from a dilute to a more concentrated solution through a partially permeable membrane
movement of water into plant roots occurs by
osmosis
active transport
the overall movement of chemicals across a cell membrane requiring energy from respiration
active transport is used in
the absorption of nitrates by plant roots
photosynthesis may be limited by
temperature- carbon dioxide- light intensity
techniques used in fieldwork to investigate the effect of light on plants
light meter- quadrat- identification key
light meter
a device used to measure the amount of light
Quadrat sampling
a classic tool for the study of ecology
Identification key
a printed or computer-aided device that aids the identification of biological entities (such as plants)
A transect
is a line across a habitat or part of a habitat
The number of organisms of each species can be observed and recorded at regular intervals along
the transect
mitochondria
organelle found in the cytoplasm which generates large quantities of energy (in the form of ATP)
mitochondria contain
enzymes for the reactions in aerobic respiration
all living organisms require energy released by respiration for
some chemical reactions in cells
movement and synthesis of large molecules and active transport
all need energy released in respiration
synthesis of polymers
required by plant cells such as starch and cellulose
synthesis of amino acids from glucose and nitrates is important as
amino acids code for essential proteins
aerobic respiration takes place in
animal and plant cells and some microorganisms
aerobic respiration
requires oxygen
equation for respiration
glucose + oxygen -> carbon dioxide + water (+ energy released)
balanced equation for respiration
C6H12O6 + 6O2 -> 6CO2 + 6H2O
anaerobic respiration takes place in
animal- plant and some microbial cells in conditions of low oxygen or absence of oxygen
examples of anaerobic respiration
plant roots in waterlogged soil- bacteria in puncture wounds- human cells during vigorous exercise
equation for anaerobic respiration in animal cells and bacteria
glucose -> lactic acid (+ energy released)
equation for anaerobic respiration in plant cells and some microorganisms like yeast
glucose -> ethanol + carbon dioxide (+ energy released)
aerobic respiration releases
more energy per glucose molecule than anaerobic respiration
anaerobic respiration of microorganisms is used in
the production of biogas and fermentation in bread making and alcohol production
Author
Anonymous
ID
296359
Card Set
Science B4
Description
Science B4
Updated
2015-02-20T13:01:18Z
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