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2.4 - Living Cells Need Energy - Coggle Diagram
2.4 - Living Cells Need Energy
What tasks occur with the use of energy?
Active Transport
Movement of Organelles
Endocytosis
Exocytosis
Synthesis of Macromolecules
What is energy?
Energy is defined as
the capacity to do work
.
More energy an organism has, the more work it can do!
Energy is never lost or destroyed and can be
transferred
or
transformed
Plants convert light energy into chemical energy via photosynthesis
Animal cells such as muscle cells can convert chemical energy via respiration into movement.
What is the difference between autotrophs and heterotrophs?
Autotrophs
Autotrophs
are
able to synthesise their own food.
Photosynthetic autotrophs
are organisms which are able to
synthesise their own food from light, using the process of photosynthesis.
Heterotrophs
Heterotrophs
must
consume other living things to gain energy.
Chemoautotrophs
are
able to produce food via chemicals
. These type of organisms live in hostile environments.
Both autotrophs and heterotrophs produce energy using the processes of:
Cellular Respiration
Aerobic
(meaning with
oxygen
)
Anaerobic
(meaning
without oxygen
)
What is the main source of energy?
The sun is the main source of energy for life.
The sun is
the principal source of energy
for living things on Earth.
Energy is transferred from the sun to the Earth in the form of
electromagnetic radiation (light)
.
This energy
is absorbed by autotrophs
that use the energy to carry out photosynthesis.
What is photosynthesis?
Photosynthesis is important in the conversion of light energy into chemical energy
Photosynthesis is a complex chemical process that converts light into chemical energy through the transformation of carbon dioxide and water into oxygen and sugars.
Chem Equation
6C0^2 + 6H^2O Light / Chlorophyll C^6H^12O^6 + 6O^2
Carbon Dioxide + Water + Light / Chlorophyll Glucose + Oxygen
Autotrophs
Autotrophs contain
light-absorbing molecules
, such as chlorophyll.
This is stored in chloroplasts (eukaryotes) or thylakoid membranes (prokaryotes) located near the cell membrane.
The light energy absorbed by autotrophs in photosynthesis is
stored in chemical bonds between the atoms in the glucose molecules.
The thylakoids are packed with chlorophyll.
These selectively absorb violet-blue and red-light wavelengths and reflect or transmit green light.
The
energy transformation
efficiency in photosynthesis is
limited
as
more than half of incident sunlight is composed of wavelengths too long to be absorbed
.
Some of the remainder is reflected or lost to surrounding tissues.
Energy Transformations
Energy cannot be created or destroyed but can be transferred and transformed.
During photosynthesis and cellular respiration,
energy is transferred into usable forms.
For example, energy is transformed from
light energy to chemical energy.
Cellular Respiration
Cellular respiration provides energy by breaking down energy-rich organic molecules into lower energy products. It releases more energy than is required.
All living organisms (plants and animals) respire to convert chemical energy (sugars) into useable energy (ATP).
This allows organisms to carry out essential processes to live, including
synthesis, active transport, movement, growth and reproduction.
There are two types of respiration
AEROBIC (with O2)
ANAEROBIC (without O2)
How autotrophs and heterotrophs transform chemical energy for use through aerobic respiration?
It can produce energy by breaking down glucose in the presence of oxygen.
The energy that is not lost as heat is stored as ATP.
𝑪𝟔𝑯𝟏𝟐𝑶𝟔 + 𝟔𝑶𝟐 → 𝟔𝑪𝑶𝟐+ 𝟔𝑯𝟐𝟎 + 𝐴𝑇𝑃
𝑔𝑙𝑢𝑐𝑜𝑠𝑒+𝑜𝑥𝑦𝑔𝑒𝑛 →𝑐𝑎𝑟𝑏𝑜𝑛 𝑑𝑖𝑜𝑥𝑖𝑑𝑒 + 𝐴𝑇𝑃 (𝑒𝑛𝑒𝑟𝑔𝑦)
Fermentation is an anaerobic alternative to aerobic respiration
Respiration without the presence of oxygen is known as anaerobic respiration or fermentation.
Occurs in the
cytoplasm
of the cells.
The products produced is dependent on the type of cell involved.
Alcoholic fermentation occurs in plants and yeast as they produce ethanol and carbon dioxide.
C6H12O6 -------------> 2(normal two)C2H5OH + 2CO2 + energy
Glucose -------> Ethanol + Carbon Dioxide + Energy
Lactic acid fermentation occurs in animals as it produces lactic acid.
C6H12O6 ----------> 2(normal two)C3H6O3 + Energy
Glucose ------> Lactic Acid + Energy
LOOK AT SLIDE 18 of PowerPoint 2.4 & 2.5 FOR Comparison Table (IMPORTANT!!!!!!!!!!!!!!)