Cells: Energy

Question 1

Energy

Answer 1

all cells require energy (the capacity to do work)

Question 2

Uses of Energy

Answer 2

• movement of organelles, active transport
• maintaining stable internal environment (conc., pH, temp.)
• synthesis of proteins, lipids, macromolecules etc.

Question 3

Sources of Energy

Answer 3

the Sun

• main source of light energy for photosynthesis in plants
• provides heat energy to maintain Earth’s atmospheric temperature (needed to survive and grow)

Autotrophs

• living organisms, can synthesis complex organic molecules from simple inorganic molecules using light energy
• undergo photosynthesis & respiration

Heterotrophs

• living organisms, cannot synthesise energy rich compounds & depend on plants to obtain energy
• undergo respiration

Question 4

Energy Transformation

Answer 4

Photosynthesis = the process of synthesis of complex organic molecules from simple inorganic molecules using light energy *equation

Respiration = the chemical process which breaks down organic “fuel”, releasing energy to make ATP, *equation

Question 5

Stages of Respiration

Answer 5

• glycolysis: anaeorbic set of reactions in cytoplasm (glucose, intermediate compounds, two pyruvates) net 2 ATP produced
• Kreb’s Cycle = pyruvates broken down into CO2 & H20 series of regulated steps controlled by specific enzymes (producing intermediate compounds & heat) -> mitochondria
• Electron Transport Phophorylation = mitochondria, further steps

Question 6

ATP Cycle

Answer 6

the continuous production & breakdown of ATP

ATP + water <> ADP + P + energy