BTEC Level 3 National Extended Diploma in
Applied Science
Unit 1: Principles and Applications of Science I
Complete Distinction-Level Revision Notes
Designed around the Pearson 2016 BTEC National Unit 1 specification: biology, chemistry and physics, with exam
technique, equations, required applications and distinction-level links.
How to use this pack: Learn the core facts first, then practise applying them to unfamiliar contexts. For Distinction, do not
just state facts: explain mechanisms, link structure to function/properties, compare alternatives, use calculations accurately,
and justify conclusions.
, 1. Unit overview and Distinction standard
Unit 1 is an externally assessed core unit. Pearson describes it as covering key science concepts in biology, chemistry and
physics. The specification includes animal and plant cells, tissues, atomic structure and bonding, chemical/physical
properties and uses of substances, and waves and their application in communications.
What Distinction answers do
• Use precise scientific terminology rather than vague wording.
• Explain cause → mechanism → effect, not just identify a fact.
• Integrate ideas from different areas of science where appropriate.
• Use equations, units and significant figures correctly and interpret the answer.
• Apply knowledge to unfamiliar vocational or realistic situations.
• Compare options using scientific evidence and justify a decision.
• Evaluate limitations, assumptions, reliability and consequences where the question requires it.
Distinction sentence pattern: “Because ___, this causes ___ through ___, therefore ___ is more suitable than ___
because ___.”
2. Biology — Cells and tissues
2.1 Eukaryotic animal cells
Nucleus: contains DNA/chromosomes and controls gene expression and cell activities. Mitochondria: site of aerobic
respiration; ATP is produced for cellular work. Ribosomes: site of protein synthesis. Rough ER: membrane network with
ribosomes; synthesised proteins can be transported. Smooth ER: lipid synthesis and other metabolic roles. Golgi
apparatus: modifies, sorts and packages proteins/lipids into vesicles. Lysosomes: membrane-bound compartments
containing digestive enzymes. Cell-surface membrane: phospholipid bilayer with proteins; selectively controls movement
and signalling. Cytoplasm: site of many metabolic reactions.
2.2 Eukaryotic plant cells
Plant cells contain the animal-cell structures above plus a cell wall made mainly of cellulose, a large permanent vacuole
containing cell sap, and chloroplasts containing chlorophyll for photosynthesis. The cell wall provides strength; the vacuole
helps maintain turgor; chloroplasts absorb light energy.
2.3 Prokaryotic cells
Bacteria are prokaryotic: they are smaller and lack a membrane-bound nucleus. DNA is located in a nucleoid region, usually
as a circular chromosome; plasmids may also occur. They have a cell membrane, cytoplasm, ribosomes and cell wall; some
have a capsule, flagellum or pili. Their simpler structure reflects their different evolutionary organisation.
2.4 Cell specialisation
Differentiation produces specialised cells with structures adapted to particular functions. Examples: red blood cells have a
biconcave shape and no nucleus when mature, increasing space for haemoglobin and gas exchange; sperm cells have a
flagellum, many mitochondria and an acrosome; ciliated epithelial cells have cilia to move mucus; root hair cells have a large
surface area for absorption; palisade cells contain many chloroplasts for photosynthesis.
2.5 Transport across membranes
• Diffusion: net movement of particles from higher to lower concentration; passive, no ATP directly required.
• Facilitated diffusion: passive movement through membrane proteins down a concentration gradient.
• Osmosis: net movement of water through a selectively permeable membrane from higher water potential to lower water
potential.
• Active transport: movement against a concentration gradient using membrane proteins and energy from ATP.
Applied Science
Unit 1: Principles and Applications of Science I
Complete Distinction-Level Revision Notes
Designed around the Pearson 2016 BTEC National Unit 1 specification: biology, chemistry and physics, with exam
technique, equations, required applications and distinction-level links.
How to use this pack: Learn the core facts first, then practise applying them to unfamiliar contexts. For Distinction, do not
just state facts: explain mechanisms, link structure to function/properties, compare alternatives, use calculations accurately,
and justify conclusions.
, 1. Unit overview and Distinction standard
Unit 1 is an externally assessed core unit. Pearson describes it as covering key science concepts in biology, chemistry and
physics. The specification includes animal and plant cells, tissues, atomic structure and bonding, chemical/physical
properties and uses of substances, and waves and their application in communications.
What Distinction answers do
• Use precise scientific terminology rather than vague wording.
• Explain cause → mechanism → effect, not just identify a fact.
• Integrate ideas from different areas of science where appropriate.
• Use equations, units and significant figures correctly and interpret the answer.
• Apply knowledge to unfamiliar vocational or realistic situations.
• Compare options using scientific evidence and justify a decision.
• Evaluate limitations, assumptions, reliability and consequences where the question requires it.
Distinction sentence pattern: “Because ___, this causes ___ through ___, therefore ___ is more suitable than ___
because ___.”
2. Biology — Cells and tissues
2.1 Eukaryotic animal cells
Nucleus: contains DNA/chromosomes and controls gene expression and cell activities. Mitochondria: site of aerobic
respiration; ATP is produced for cellular work. Ribosomes: site of protein synthesis. Rough ER: membrane network with
ribosomes; synthesised proteins can be transported. Smooth ER: lipid synthesis and other metabolic roles. Golgi
apparatus: modifies, sorts and packages proteins/lipids into vesicles. Lysosomes: membrane-bound compartments
containing digestive enzymes. Cell-surface membrane: phospholipid bilayer with proteins; selectively controls movement
and signalling. Cytoplasm: site of many metabolic reactions.
2.2 Eukaryotic plant cells
Plant cells contain the animal-cell structures above plus a cell wall made mainly of cellulose, a large permanent vacuole
containing cell sap, and chloroplasts containing chlorophyll for photosynthesis. The cell wall provides strength; the vacuole
helps maintain turgor; chloroplasts absorb light energy.
2.3 Prokaryotic cells
Bacteria are prokaryotic: they are smaller and lack a membrane-bound nucleus. DNA is located in a nucleoid region, usually
as a circular chromosome; plasmids may also occur. They have a cell membrane, cytoplasm, ribosomes and cell wall; some
have a capsule, flagellum or pili. Their simpler structure reflects their different evolutionary organisation.
2.4 Cell specialisation
Differentiation produces specialised cells with structures adapted to particular functions. Examples: red blood cells have a
biconcave shape and no nucleus when mature, increasing space for haemoglobin and gas exchange; sperm cells have a
flagellum, many mitochondria and an acrosome; ciliated epithelial cells have cilia to move mucus; root hair cells have a large
surface area for absorption; palisade cells contain many chloroplasts for photosynthesis.
2.5 Transport across membranes
• Diffusion: net movement of particles from higher to lower concentration; passive, no ATP directly required.
• Facilitated diffusion: passive movement through membrane proteins down a concentration gradient.
• Osmosis: net movement of water through a selectively permeable membrane from higher water potential to lower water
potential.
• Active transport: movement against a concentration gradient using membrane proteins and energy from ATP.
