State the 3 principles of cell theory
1.All living things are made up of one or more cells
2. Cells are the most basic unit of structure and function in all living things.
3. All cells are created from pre-existing cells.
Define unicellular and multicellular
Unicellular is single cells
Multicellular is made up of more than one cell
The difference between eukaryotic and prokaryotic
Eukaryotic cells are complex and include all animal and plants cells as well as yeasts, other fungi and algae. Prokaryotic cells are simpler and smaller and include bacteria. However both types of cells have membranes, cytoplasm and DNA.
organism
An individual plant, animal or single-cell lifeform
cytoplasm
The fluid component of the cell, enclosed by the cell membrane and surrounding organelles
Phospholipid
A large molecules formed from a glycerol molecule covalently bound to two fatty acid molecules and a phosphate group. It has a hydrophillic head (because of phosphate) and a hydrophobic tail (because of fatty acids)
What is the structure and function of a cell-surface membrane in an eukaryotic cell
This is found around the outside of the cell and consists of a phospholipid bilayer together with proteins, antigen and other components. The cell-surface membrane controls entry and exit of the substances into and out of the cell.
The structure and function of the nucleus and the nucleolus in a eukaryotic cell
The nucleus is the largest organelle and is surrounded by the nuclear envelope. This is a double membrane that has many gaps or pores. The nucleus stores genetic information, in the form of DNA.
The nucleolus is a smaller, non-membrane-bound structure found in the nucleus, primarily responsible for synthesising ribosomal and assembling ribosomes
The structure and function of the Mitochondria
The site of aerobic respiration and therefore the site of ATP production. Aerobic respiration creates energy that is used to produce ATP. ATP is used in most processes in the cell that require energy.
What is a phospholipid bilayer
A double layer of phospholipids with the hydrophobic tails arranged towards the middle and the hydrophilic head groups on the outside. It forms the basis of all the biological membranes
Structure and function of ribosomes
Site of protein synthesis. Some float free in the cytoplasm and make the proteins needed within the cell, where as others are attached to the rough endoplasmic reticulum. Ribosomes use the information gathered by the messenger RNA Molecule to assemble the correct amount of amino acids in the protein. This process is know as translation
The structure and function of the smooth and rough endoplasmic reticulum
. The RER has ribosomes attached to its outer surface. Proteins that will be released from the cell or incorporated into the plasma membrane are made on these attached ribosomes and then folded, packaged and transported in the RER to the golgi apparatus.
The SER does not have attached ribosomes and is responsible for synthesising, storing and transporting lipids and some carbohydrates
Phospholipid bilayer
A double layer of phospholipids with hydrophobic tails arranged towards the middle and the hydrophobic head groups on the outside
Golgi apparatus and golgi vesicles
The golgi modifies proteins that have been transported from the RER. These modified proteins are then packaged for transport by golgi vesicles
Lysosomes
When proteins and other cell components get worn out, they are moved into lysosomes. Digestive enzymes in the lysosomes break down the cell components. Lysosomes are also involved in digestion of invading pathogens (bacteria and viruses)
Centrioles
Involved in the formation of the spindle in mitosis
Mitosis
INTERPHASE- the cell grows and the DNA replicates
PROPHASE- the chromosomes condense and the nucleolus disappears
METAPHASE- The chromosomes align in the center of the cell and attach to spindle
ANAPHASE- Chromatids separate and move to opposite poles of the cell
TELOPHASE- two new nuclei form around each set of chromosome
CYTOKINESIS- The cytoplasm of the parent cell splits to form two identical daughter cells
4 phases of mitosis
Prophase, metaphase, anaphase, telophase
Define chromatids
Two identical copies of a chromosome formed by DNA replication
Cytokinesis
The cytoplasm divides to form two daughter cells after mitosis
Stem cells
Undifferentiated (non-specialised) cels that can give rise to one or more types of differentiated (specialised) cell.
Erythrocytes
Red blood cells. The carry oxygen around the body using the pigment haemoglobin. They lack nuclei and most other organelles, which means more haemoglobin can be packed into the cytoplasm. They have a bioconcave shape, this increase surface area to allow for more efficient diffusion of oxygen into the cell. The elastic plasma membrane allows the cell to change so it can squeeze through narrow capillaries
Squamous epithelial cells
They are flattened cells, supported by a basement membrane, that makes up the epithelium. This makes them well suited for exchange surface, such as in lungs, gut and kidneys.
