Cells and digestion Flashcards
What is active transport?
The movement of substances from an area of low concentration too an area of high concentration . Because it goes against the concentration gradient the use of ATP energy is required and a carrier protein
What is the differences between prokaryotic and eukaryotic cells ?
Size- prokaryotic have a diameter of 2 micrometers. Eukaryotic cells have a diameter of 10 micrometers
Nucleus-Prokaryotic has no nucleus while Eukaryotic does have a nucleus
Type of DNA- Prokaryotic cells only have one loop of DNA . Eukaryotic cells DNA is linear
Organelles-Prokaryotic cells have few organelles while Eukaryotic cells have many organelles
Cell cycle
Interphase- Cells grow in size , DNA and organelles replicate
Mitosis-replicated chromosomes line up along the centre of the cell and are pulled to opposite poles the nucleus then divides
Cytokinesis-cell membrane and cytoplasm divide to form 2 new identical daughter cells
What is a stem cell?
A cell that has not yet become specialized
Advantages and disadvantages of embryonic stem cells
A= Can develop into any type of cell and therefore can treat a variety of issues. Painless
D= embryos cannot give consent. Embryo could be damaged or killed .
Advantages and disadvantages of adult stem cells
A=plentiful supply and the adult can give permission
D= painful tp extract. Fewer diseases can be treated because the cells can only take the form of what they were taken from
Hierarchy of organisms
Cells Tissues Organs Organ system Organisms
How do enzymes work?
Enzymes are proteins . They speed up the rate of chemical reactions
They have a specific shape called the active site
The active site is complementary to the shape of the substrate molecule .(lock and key theory).
There are random collisions between the enzyme and the substrate . When the substrate enters the active site an enzyme substrate complex is formed
Bonds are then broken and the produce is released throughout the body.
How do high temperatures effect enzymes ?
In higher temperatures both enzymes and the substrate molecules have more kinetic energy meaning collisions are more frequent.
However over 40 degrees and the active site of the enzyme becomes denatured meaning it’s shape changes preventing the specific substrate from entering. The enzyme no longer functions
What is bile
A green alkaline liquid produced by the liver and stored in the gallbladder . It neutralises stomach acids and emulsifies fat
Where is food absorbed into the blood stream ?
Small intestine
Where is water reabsorbed into the bloodstream
Large intestine
What is diffusion
Net movement of molecules from a region of high concentration to an area of low concentration gradient
What is osmosis
Movement of water molecules through a partially permeable membrane from an area of high concentration to an area of low concemtration
