IBANGA 10 Grade 10 Life
Sciences Term 4:
Paper 1
, Chemistry of Life
Organic & Inorganic Compounds
• Inorganic Compounds: Water (universal solvent, temperature regulator) and
minerals (Macronutrients: Ca, P, N; Micronutrients: Fe, I).
• Organic Compounds: Carbohydrates (energy), Lipids (storage, insulation),
Proteins (growth, repair), and Nucleic Acids (DNA/RNA).
Enzymes (Crucial Exam Topic)
• Definition: Biological catalysts that speed up chemical reactions by lowering
activation energy.
• Mechanism: Works on a "Lock and Key" model where a specific substrate fits
into the enzyme's active site.
• Denaturation: High temperatures and extreme pH levels change the shape of
the active site, permanently rendering the enzyme inactive. Low temperatures
only deactivate enzymes temporarily.
Nutrient Deficiencies
• Kwashiorkor: Caused by a lack of protein; causes a swollen abdomen.
• Scurvy: Caused by a lack of Vitamin C; causes bleeding gums.
• Rickets: Caused by a lack of Vitamin D/Calcium; causes malformed, weak
bones.
• Anaemia: Caused by a lack of Iron; results in a lack of oxygen transport in the
blood.
Cells & Mitosis
Cell Organelles & Functions
• Cell Wall: Rigid outer layer in plant cells made of cellulose; provides structural
support.
• Cell Membrane: Selectively permeable boundary controlling what enters and
leaves the cell.
• Nucleus: Contains DNA; controls all cellular activities.
• Mitochondrion: Site of cellular respiration (produces ATP energy).
• Chloroplast: Site of photosynthesis in plant cells; contains chlorophyll.
Sciences Term 4:
Paper 1
, Chemistry of Life
Organic & Inorganic Compounds
• Inorganic Compounds: Water (universal solvent, temperature regulator) and
minerals (Macronutrients: Ca, P, N; Micronutrients: Fe, I).
• Organic Compounds: Carbohydrates (energy), Lipids (storage, insulation),
Proteins (growth, repair), and Nucleic Acids (DNA/RNA).
Enzymes (Crucial Exam Topic)
• Definition: Biological catalysts that speed up chemical reactions by lowering
activation energy.
• Mechanism: Works on a "Lock and Key" model where a specific substrate fits
into the enzyme's active site.
• Denaturation: High temperatures and extreme pH levels change the shape of
the active site, permanently rendering the enzyme inactive. Low temperatures
only deactivate enzymes temporarily.
Nutrient Deficiencies
• Kwashiorkor: Caused by a lack of protein; causes a swollen abdomen.
• Scurvy: Caused by a lack of Vitamin C; causes bleeding gums.
• Rickets: Caused by a lack of Vitamin D/Calcium; causes malformed, weak
bones.
• Anaemia: Caused by a lack of Iron; results in a lack of oxygen transport in the
blood.
Cells & Mitosis
Cell Organelles & Functions
• Cell Wall: Rigid outer layer in plant cells made of cellulose; provides structural
support.
• Cell Membrane: Selectively permeable boundary controlling what enters and
leaves the cell.
• Nucleus: Contains DNA; controls all cellular activities.
• Mitochondrion: Site of cellular respiration (produces ATP energy).
• Chloroplast: Site of photosynthesis in plant cells; contains chlorophyll.
