YEAR 11 Flashcards
What are the 3 ways substances move in / out of cells
Osmosis
Diffusion
Active transport
What is active transport
Substances move UP their concentration gradient - needs energy
What are the 3 factors affecting rate of diffusion
Sf area
Temperature
Concentration gradient
Why do alveoli allow for efficient gas exchange
Capillary is only 1 cell thick - short diffusion distance
Vast sf area of millions of alveoli
Where does oxygen enter the blood
Via alveoli
Where does glucose enter the blood
From food broken down in small intestine
From glycogen store in liver
Where do amino acids enter the blood
From food broken down in small intestine
Where does carbon dioxide enter the blood
From all respiring cells into the capillaries
Where does urea enter the blood
From the breakdown of proteins and amino acids in the LIVER
Where do antibodies enter the blood
Produced by B lymphocytes
What is urea
A waste product formed from the breakdown of amino acids and proteins
How are red blood cells adapted to their function
Biconcave shape - high sf area to maximise diffusion of oxygen
Red pigment to haemoglobin
Lack of nucleus makes room for haemoglobin
What is a phagocyte
Immune cell that protects the body by engulfing and digesting foreign particles
What is a B Lymphocyte
Produces antibodies to kill microorganisms
Contain lots of ribosomes to make proteins
What are platelets
Fragments of cells used in blood clotting
What is the purpose of blood clots
To stop blood loss
To prevent pathogens from entering the bloodstream
What is plasma
The liquid part of blood
Transports nutrients and useful molecules
Which way do arteries move blood
AWAY from the heart
Which way do veins move blood
TOWARDS the heart
