Biology Paper 1 Notes
Key concepts:
1.1 Explain how the sub-cellular structures of eukaryotic and prokaryotic cells are related to their functions,
including:
Animals and plants are formed from cells. The parts in a cell have particular functions in a cell.
Cells with a nucleus and membrane-bound organelles such as mitochondria are called eukaryotic cells. Cells without a
nucleus are called prokaryotic cells.
An animal cells – nucleus, cell membrane, mitochondria, and ribosomes
Animal cells are eukaryotic as they have nuclei.
They include the nucleus, cell membrane, mitochondria, ribosomes, and cytoplasm. Nucleus: A large structure that
contains genes. Controls the activities of the cell.
Cell membrane: Controls what enters and leaves the cell e.g., oxygen, carbon dioxide and glucose.
Mitochondria: (single: mitochondrion), tiny structures where respiration takes place. It releases energy for the cell
processes.
Ribosomes: Found in the cytoplasm. Where the proteins are made, called protein synthesis.
Cytoplasm: Jelly like substance that fills the cell. Where many reactions take place.
B plant cells – nucleus, cell membrane, cell wall, chloroplasts, mitochondria, vacuole, and ribosomes
Plant cells are eukaryotic as they also include a nucleus.
They include the nucleus, cell membrane, mitochondria, ribosomes, cell wall, chloroplast, and a vacuole.
The parts in a plant cell that are the same in the animal cell have the same functions but only include a few more
structures such as the cell wall chloroplast and the vacuole.
Cell wall: provides the cell with structural protection and support e.g., to help keep its shape.
Chloroplast: part of the cell where photosynthesis takes place to make food for the plant cell.
Vacuole: The large central vacuole contains the cell sap, which helps to keep the plant cell rigid.
C bacteria – chromosomal DNA, plasmid DNA, cell membrane, ribosomes, and flagella
Bacteria is a specialized cell. It has a different kind of cell structure from plant and animal cells.
They are prokaryotic as they do not have a nucleus.
They include chromosomal DNA, plasmid DNA, cell membrane, ribosomes, and flagella.
Chromosomal DNA: A single loop of chromosomal DNA lies free in the cytoplasm. Where most of the bacterial genes are
carried.
Plasmid DNA: Plasmid DNA contains additional genes that are not found in the chromosomes.
Flagella: a tail-like structure that helps the cell move.
1.2 Describe how specialised cells are adapted to their function, including:
Specialised cells are cells that are specialised for different functions. Bacteria cells are a type of specialised cell.
A sperm cells – acrosome, haploid nucleus, mitochondria, and tail
A sperm cell is a sex cell and also a specialised cell.
Acrosome: Helps the sperm cell penetrate into the egg cell.
Haploid nucleus. Contains genetic material for fertilisation.
Tail: Heps the cell swim towards the egg cell.
b egg cells – nutrients in the cytoplasm, haploid nucleus, and changes in the cell membrane after fertilisation
Cytoplasm including nutrients: Supplies nutrients to help the egg survive.
Change in cell membrane after fertilisation: The cell membrane hardens after a sperm cell has entered to allow no more
sperm cells to enter.
, c ciliated epithelial cells
Ciliated epithelial cells have a nucleus, cell membrane, mitochondria, cytoplasm, ribosomes, and Cilla. Epithelial cells line
tubes such as the trachea. Cilla moves things along the tube such as mucus This cell has a lot of Cilla to move mucus,
containing dirt and bacteria, away from the lungs.
1.3 Explain how changes in microscope technology, including electron microscopy, have enabled us to see cell
structures and organelles with more clarity and detail than in the past and increased our understanding of the role of
subcellular structures
Before microscopes, people were unable to see the subcellular structures of cells.
A light microscope uses light to magnify objects. The greatest magnification in a light microscope is X2000.
An electron microscope uses electrons to magnify and look at objects. It has a magnification greatest of X10 million. You
can see it with more clarity and detail than a light microscope.
1.4 Demonstrate an understanding of number, size, and scale, including the use of estimations and explain when they
should be used
MATHS SKILLS +
1.5 Demonstrate an understanding of the relationship between quantitative units in relation to cells, including: a milli
(10−3) b micro (10−6) c nano (10−9) d pico (10−12) e calculations with numbers written in standard form
1.6 Core Practical: Investigate biological specimens using microscopes, including magnification calculations, and
labelled scientific drawings from observations
Read over pages 5 and 6 in the revision guide.
1.7 Explain the mechanism of enzyme action including the active site and enzyme specificity
Enzymes are biological catalysts. They speed up reactions without being used up themselves.
In an enzyme there is an active site where only the matching shape of substrate molecules can fit into and hold together
to form bonds, therefore a product can be made. A product molecule doesn’t fit back into the active site so therefore is
released.
A key and Lock example can be used to show the enzyme activity, the active site being the lock and the substrate
molecule being the key.
Key concepts:
1.1 Explain how the sub-cellular structures of eukaryotic and prokaryotic cells are related to their functions,
including:
Animals and plants are formed from cells. The parts in a cell have particular functions in a cell.
Cells with a nucleus and membrane-bound organelles such as mitochondria are called eukaryotic cells. Cells without a
nucleus are called prokaryotic cells.
An animal cells – nucleus, cell membrane, mitochondria, and ribosomes
Animal cells are eukaryotic as they have nuclei.
They include the nucleus, cell membrane, mitochondria, ribosomes, and cytoplasm. Nucleus: A large structure that
contains genes. Controls the activities of the cell.
Cell membrane: Controls what enters and leaves the cell e.g., oxygen, carbon dioxide and glucose.
Mitochondria: (single: mitochondrion), tiny structures where respiration takes place. It releases energy for the cell
processes.
Ribosomes: Found in the cytoplasm. Where the proteins are made, called protein synthesis.
Cytoplasm: Jelly like substance that fills the cell. Where many reactions take place.
B plant cells – nucleus, cell membrane, cell wall, chloroplasts, mitochondria, vacuole, and ribosomes
Plant cells are eukaryotic as they also include a nucleus.
They include the nucleus, cell membrane, mitochondria, ribosomes, cell wall, chloroplast, and a vacuole.
The parts in a plant cell that are the same in the animal cell have the same functions but only include a few more
structures such as the cell wall chloroplast and the vacuole.
Cell wall: provides the cell with structural protection and support e.g., to help keep its shape.
Chloroplast: part of the cell where photosynthesis takes place to make food for the plant cell.
Vacuole: The large central vacuole contains the cell sap, which helps to keep the plant cell rigid.
C bacteria – chromosomal DNA, plasmid DNA, cell membrane, ribosomes, and flagella
Bacteria is a specialized cell. It has a different kind of cell structure from plant and animal cells.
They are prokaryotic as they do not have a nucleus.
They include chromosomal DNA, plasmid DNA, cell membrane, ribosomes, and flagella.
Chromosomal DNA: A single loop of chromosomal DNA lies free in the cytoplasm. Where most of the bacterial genes are
carried.
Plasmid DNA: Plasmid DNA contains additional genes that are not found in the chromosomes.
Flagella: a tail-like structure that helps the cell move.
1.2 Describe how specialised cells are adapted to their function, including:
Specialised cells are cells that are specialised for different functions. Bacteria cells are a type of specialised cell.
A sperm cells – acrosome, haploid nucleus, mitochondria, and tail
A sperm cell is a sex cell and also a specialised cell.
Acrosome: Helps the sperm cell penetrate into the egg cell.
Haploid nucleus. Contains genetic material for fertilisation.
Tail: Heps the cell swim towards the egg cell.
b egg cells – nutrients in the cytoplasm, haploid nucleus, and changes in the cell membrane after fertilisation
Cytoplasm including nutrients: Supplies nutrients to help the egg survive.
Change in cell membrane after fertilisation: The cell membrane hardens after a sperm cell has entered to allow no more
sperm cells to enter.
, c ciliated epithelial cells
Ciliated epithelial cells have a nucleus, cell membrane, mitochondria, cytoplasm, ribosomes, and Cilla. Epithelial cells line
tubes such as the trachea. Cilla moves things along the tube such as mucus This cell has a lot of Cilla to move mucus,
containing dirt and bacteria, away from the lungs.
1.3 Explain how changes in microscope technology, including electron microscopy, have enabled us to see cell
structures and organelles with more clarity and detail than in the past and increased our understanding of the role of
subcellular structures
Before microscopes, people were unable to see the subcellular structures of cells.
A light microscope uses light to magnify objects. The greatest magnification in a light microscope is X2000.
An electron microscope uses electrons to magnify and look at objects. It has a magnification greatest of X10 million. You
can see it with more clarity and detail than a light microscope.
1.4 Demonstrate an understanding of number, size, and scale, including the use of estimations and explain when they
should be used
MATHS SKILLS +
1.5 Demonstrate an understanding of the relationship between quantitative units in relation to cells, including: a milli
(10−3) b micro (10−6) c nano (10−9) d pico (10−12) e calculations with numbers written in standard form
1.6 Core Practical: Investigate biological specimens using microscopes, including magnification calculations, and
labelled scientific drawings from observations
Read over pages 5 and 6 in the revision guide.
1.7 Explain the mechanism of enzyme action including the active site and enzyme specificity
Enzymes are biological catalysts. They speed up reactions without being used up themselves.
In an enzyme there is an active site where only the matching shape of substrate molecules can fit into and hold together
to form bonds, therefore a product can be made. A product molecule doesn’t fit back into the active site so therefore is
released.
A key and Lock example can be used to show the enzyme activity, the active site being the lock and the substrate
molecule being the key.
