General Knowledge Flashcards
What is the end-product of digestion of proteins?
Amino acids
Which enzymes are found in the microbodies (peroxisomes) and what is their purpose?
Catalase
Catalyses hydrogen peroxide (toxic)to water and oxygen
What is the tonoplast?
The membrane around a cell vacuole
What are plastids?
These are organelles containing pigments.
Examples of plastids include chloroplasts and leucoplasts
What is the cell wall of prokaryotes made of?
Murein (amino acids and polysaccharides)
What size are the ribosomes in prokaryotes and eukaryotes respectively?
70S (smaller) in prokaryotes
80 S (larger) in eukaryotes; however the mitochondrial ribosomes and those in chloroplasts are also 70S therefore eukaryotes have both 70S and 80S
What makes a substance polar?
And what is the effect of polarity on a substance?
- Uneven charge distribution within the molecules
- Makes it soluble in water eg water molecules are dipolar( , Phosphate heads of phospholipids, carbohydrate heads of glycolipids
Which enzyme catalyzes the breakdown of starch to maltose?
Amylase
Which enzyme catalyses the breakdown of maltose to glucose?
Maltase
What makes a substance polar? And what is the effect of polarity on a substance?
- Uneven charge distribution within the molecules
- Makes it soluble in water eg water molecules are dipolar(Phosphate heads of phospholipids, carbohydrate heads of glycolipids
What is the arrangement of four bonds (as in methane) on a carbon atom called?
Tetrahedral arrangement
Which hormone converts glycogen to glucose?
Insulin
Which hormone stimulates contractions during pregnancy?
Oxytocin
Which hormone is responsible for the breakdown of cellulose to glucose?
Cellulase
What is special about hydrogen bonds?
- They are individually weak but collectively strong
- Are constantly breaking and being formed
What is metabolism?
The sum of biochemical processes in the body
Which enzyme catalyzes the breakdown of hydrogen peroxide to water and oxygen gas?
Catalase enzyme
Give examples of cells that lack mitochondria
- Red blood cells
- Phloem cells
True or false
When fats are oxidized, water is a product
True
(This metabolic water can be useful to desert animals which store fat for this purpose)
Are lipids soluble or insoluble and why?
Insoluble
(They are non-polar and their molecules do not form hydrogen bonds with water molecules)
What is the protein found in milk called?
Casein
Another name for murein (the constituent of the cell wall of prokaryotic cells) is ?
Peptidoglycan
Why don’t plant cells burst upon intake of a lot of water but animal cells do?
Plant cells have a rigid cellulose cell wall that prevents bursting of the cell upon intake of water while the cell wall is absent in animal cells (only have a cell membrane) thus it may burst when too much water is taken in.
What is an adaptation of the anus to its function?
It has muscles that contract and enable it to expel wastes
