Biology- Topic 8/ Exchange and transport in animals Flashcards
Why do we need to transport oxygen in and out of Humans?
Lungs diffuse oxygen out and into the blood stream via the alveoli. Oxygen needs to be transported in order to react with glucose to make ATP (energy) in cells and give them energy.
Why do we need to transport carbon dioxide out of the human body?
The reaction of ATP causes the waste product carbon dioxide which needs to be diffused out of the body.
How is Carbon dioxide transported out of the human body? Simple.
Carbon dioxide binds to the haemoglobin which is transported to the lungs, diffused into the alveoli in gas exchange and exhales.
Why do we need to transport water in the human body?
In- Helps create bodily fluids such as blood
Out- washes out waste products in urine
Why do we need to transport dissolves food molecules in the human body?
Food molecules are needed to keep our cells functioning e.g glucose for energy and proteins for growth and repair.
Why do we need to transport mineral ions in the human body?
Minerals are needed to build strong bones, maintain bodily fluids and help convert food into energy.
Why do we need to transport urea out of the human body?
Urea is a metabolic product of protein break down, if too much builds up it can be toxic, therefore it is excreted through urine.
Surface to volume ratio
The ratio between the how much area there is compared to how much room inside there is. As cell size increases, the volume increases faster than the surface area, this is very inefficient for diffusion.
Surface area
the area of each face added together
Volume
Height x Width x Depth
Hotter climates SA:V
Hotter climates mean organisms want to loose heat, therefore larger surface area to absorb oxygen and loose heat is beneficial.
Colder climates SA:V
Larger volume means losing heat is reduced as heat has a larger diffusion distance.
Why multi-cellular need a transport system SA:V?
Due to a smaller SA:V we need a transport system to move substances to the cells inside the body.
How are alveoli adapted?
Large Surface area- More diffusion
One cell thick- Thin diffusion distance
Moist walls- Gases dissolve in moist conditions.
How are Erythrocytes/ red blood cells suited for their function?
Biconcave shape- larger surface area to carry oxygen and more flexible to squeeze through capillaries.
No nuclease- increases space for substances
Haemoglobin- can bind 12x more oxygen molecules.
