Surface Area and Volume Ratio
Gill lamellae and gill filaments
Name two structural features of the gills of a fish that increase their surface area.
Name the proccess by which oxygen reaches the cells inside the body of a flatworm
Highly folded cell - surface membrane
What are microvilli?
What is the name of the system that fish rely on for gas exchange
The Counter Current Principle
Spiracles
Name the structure through which gases enter and leave the body on an organism
Larger organisms have a smaller SA:V ratio however by having a specialised exchange and transport system it can overcome the long diffusion pathway.
Explain the advantage for larger animals of having a specialised system that facilitates oxygen uptake
Single cell layer or thin/flat cells or thin
Describe and explain one adaptation of a single alveolus for gas exchange
Add biuret
Describe a biochemical test to show the presence of protein.
Charged/polar
Binds/associates/loads with oxygen
Explain a property of iron ions that enables these ions to carry out their role in red blood cells.
As surface area to volume ratio increases, metabolic rate increases
A larger surface area to volume ratio will lose more heat
A higher rate of metabolism/respiration
Describe and explain the relationship between surface area to volume ratio of the human body and metabolic rate.
Diaphragm (muscle) contracts pulling diaphragm down
External intercostal muscles contract pulling/moving ribs upwards/outwards
Volume increase and pressure decrease in thoracic cavity
Describe how we breathe in
Combine/mix/join with bile salt
Make more soluble in water
Micelles breakdown close to cells
Diffuses into cells/ileum
Vitamin A is a fat-soluble substance. Micelles are involved in the process of vitamin A absorption. Describe the process of vitamin A absorption into cells lining the ileum
Arteriole
Circular/smooth muscle relaxes
Vasodilation increases blood flow
Name the type of blood vessel that controls blood flow to muscles and explain how these blood vessels change blood flow during exercise
Water column
No barrier to water movement
Cohesion from H bonds between water molecules
Water moves from xylem into cells creates tension
Lignin is a polymer found in the walls of xylem vessels in plants. Lignin keeps the xylem vessel open as a continuous tube. Explain the importance of the xylem being kept open as a continuous tube.
Hydrolysis Of glycosidic bond
Starch to maltose by amylase
Maltose to glucose by disaccharidase/maltase which are Membrane-bound
Describe the complete digestion of starch by a mammal
Hydrolysing peptide bonds
Endopeptidases act in the middle of the protein to Produce shorter polypeptide chains
Exopeptidase act on the ends of the polypeptide to produce dipeptides
Dipeptidase produces single amino acids
Describe the role of enzymes in the digestion of proteins in a mammal
Spiracles, tracheae, tracheoles - allow diffusion
Tracheoles are highly branched so large surface area
Tracheole walls thin so short diffusion distance to cells
Tracheole walls are permeable to oxygen/air
Cuticle/chitin/exoskeleton so reduce water loss
Spiracles close so no/less water loss
Describe how the structure of the insect gas exchange system: • provides cells with sufficient oxygen • limits water loss
salivary amylase
starch to maltose (in salivary glands)
salivary amylase denatured in stomach due to acidic pH
pancreatic amylase continues to hydrolyse starch to maltose
in small intestine
maltase (embedded in membrane of epithelial cells)
maltase to glucose
hydrolysis
of glycosidic bonds
Describe the role of the enzymes in the digestive system to complete the breakdown of starch
Microvilli provide large surface area
Many mitochondria to produce ATP to provide energy for active transport
Carrier proteins for active transport
Channel proteins for facilitated diffusion
Membrane bound enzymes that digest disaccharides
and co-transport of sodium ions and glucose
The epithelial cells that line the small intestine are adapted for the absorption of glucose, explain how
Sucrose actively transported into phloem
By companion/transfer cells
Lowers water potential in phloem and water enters from xylem by osmosis
Produces higher hydrostatic pressure
Mass flow to respiring cells
Describe the transport of carbohydrate in plants