3.1.3 Movement Of Cells Flashcards
What are triglycerides made of?
Glycerol and Fatty Acids
What is Glycerol?
A small 3 carbon molecule with 3 alcohol (OH) groups
What are fatty acids?
Long molecules made of a non polar hydrocarbon chain with a polar carboxyl acid group at one end
How long can the hydrocarbon chain of a fatty acid be?
Between 14 and 22 CH2 units long.
What is a simplified way of writing the formula for a fatty acid?
R-COOH
How are triglycerides formed?
One glycerol molecule joins 3 fatty acid molecules by ester bonds in a condensation polymerisation reaction
How many water molecules are produced per Triglyceride molecule in a condensation reaction?
3, because 3 bonds are made.
Are fats soluble or insoluble in water?
Insoluble in water.
What are fats/triglycerides used for?
Storage, insulation and protection.
Why are fats not used for quick energy requirements in the body if they yield more energy per unit mass than other compounds?
Their insolubility means they can’t be mobilised quickly.
What makes a fatty acid saturated, in terms of its molecular structure?
If it has no C=C bonds.
What is the key characteristic of a saturated fat?
High melting point; solid at room temperature
What makes a fatty acid unsaturated?
The presence of C=C bonds in the fatty acid chains.
What is the key characteristic of unsaturated fat?
Low melting point; liquid at room temperature
What is used to denote the position of a double bond in an unsaturated fatty acid?
Omega Numbers (omega-3, e.g.)
What are the two most common lipids?
Triglycerides and Phospholipids
What is a phospholipid and how does it differ from a triglyceride?
Have the same structure as a triglyceride but with a phosphate group in place of one fatty acid
What is a key characteristic of phospholipids?
They have polar hydrophilic heads (phosphate) and non-polar hydrophobic tails (fatty acid)
What are phospholipids the key component of?
Cell membranes
What occurs when phospholipids are mixed with water?
A liposome is created; droplet spheres with a phospholipid bilayer, where the heads face the water and the tails face each other. A compartment of water is trapped in the centre.
Biochemical test for lipids
Vigorously shake test sample with 4 ml of ethanol, decant liquid into second tube of water. If lipids are present, they will precipitate in the water and form a cloudy white emulsion
What is a prokaryotic cell?
Cells without a nucleus. Often bacteria cells.
What is a eukaryotic cell?
A cell with a nucleus. Animal, plant, fungal and protictista cells
What is cytoplasm/cytosol?
The solution within the cell membrane which contains enzymes for glycolysis and other metabolic reactions
What is a Nucleus?
The largest organelle. Surrounded by a nuclear envelope. The interior is called the nucleoplasm which is full of chromatin, which becomes condensed into discrete observable chromosomes during cell division.
What is a nucleolus?
A dark region of chromatin involved in the making of ribosomes
What is chromatin?
The DNA Protein Complex?
What are mitochondria?
An organelle where aerobic respiration takes place in all eukaryotic cells.
In what form do mitochondria release energy?
ATP
Why do muscle cells have a lot of mitochondria?
They require more energy than other cells
Explain the structure of a mitochondrion
A permeable outer membrane and an inner membrane which is folded into ‘cristae’ to give it large surface area. The area within the inner membrane is the mitochondrial matrix and contains small circular strands of DNA. Inner membrane is studded with stalked particles which are enzymes which make ATP
What are ribosomes?
They are the site of protein synthesis and are either found free in the cytoplasm making proteins for the cells own use or are found attached to the Endoplasmic Reticulum where they make proteins for export from the cell
What is the Endoplasmic reticulum?
A series of membrane channels involved in synthesising and transporting materials
What is a Rough Endoplasmic reticulum?
An ER which is studded with ribosomes which synthesises and processes proteins for export from the cell via the Golgi Apparatus
What is a Smooth Endoplasmic Reticulum?
An ER without ribosomes which is used to process materials like lipids which are needed by the cell
What is the Golgi Body?
A series of flat membrane vesicles formed by the ER to transport proteins from the RER to the cell membrane.