Cell Biology

• The structures inside a cell are called sub cellular structures
• Animal cells contain a nucleus, cytoplasm, cell membrane, mitochondria, and ribosomes.
• The nucleus controls activities of the cell and contains genetic material.
• The cytoplasm is where most of the chemical reactions take place.
• The cell membrane controls the passage of substances into and out of the cell.
• The mitochondria is where aerobic respiration takes place.
• Ribosomes are where proteins are made.
• Plant cells are similar to Animal cells but have more structures.
• The cell wall strengthens the cell
• The vacuole supports the plant
• Chloroplasts absorb light to make glucose (food) through the process of photosynthesis
• The 2 types of cell are prokaryotic and eukaryotic
• Bacterial cells are prokaryotic
• Prokaryotic cells are smaller in size than Eukaryotic cells
• Prokaryotic cells do not contain mitochondria or chloroplasts
• In bacterial cells, the cytoplasm takes over the role of the mitochondria and chloroplasts
• DNA in a bacterium is found in the cytoplasm
• Plasmids are small rings of DNA found in a bacterial cell
• The ability to see 2 or more objects as separate objects is called resolution
• An electron microscope passes electrons through the specimen and allows cells to be seen in much finer detail.#
• The magnification is how many times larger the image is than the real object
• In order to multiply bacteria use cell division called binary fission, an example of asexual reproduction.
• Bacteria can be grown in a nutrient broth solution or as colonies on a type of jelly called agar. This is called a culture.
• The agar is usually in the bottom of flat dish called a petri dish
• The nucleus of a cell contains chromosomes made of DNA
• Each chromosome carries many genes
• Unspecialised cells are referred to as undifferentiated
• Undifferentiated cells can divide to make different types of cells. They are called stem cells.
• Embryonic stem cells are from the embryo
• Adult stem cells are found in some organs and tissues
• Stem cells can be used to treat conditions where cells are damaged or not working properly such as diabetes and paralysis.
• Stem cells can transfer viral infections
• A cloned embryo of a patient may be used as a source of stem cells. This is known as therapeutic cloning.
• Diffusion is the movement of particles from an area of high concentration to an area of low concentration. An example of this would be oxygen and carbon dioxide moving during gas exchange in the lungs.
• A single celled organism has a large surface area to volume ratio. This allows enough molecules to diffuse into and out of the cell.
• Multicellular organisms have a smaller surface are to volume ratio than single celled organisms.
• Active transport is the movement of substances from an area of high concentration to an area of low concentration. It allows mineral ions to be absorbed into plant root hairs and sugar molecules to be absorbed in the gut.