bio definitions

Nutrients

Chemical substance in food that provide energy and materials needed by the body.

maltose

glucose + glucose

lactose

glucose + galactose

sucrose

glucose + fructose

enzymes

biological catalysts, they speed up rate of chemical reactions without themselves being chemically changed at the end of the chemical reaction.

catabolic reaction

chemical reaction which breaks down complex molecules into simpler molecules

anabolic reaction

chemical reaction which build up simpler molecules into complex molecules

limiting factor

is a factor that directly affects the rate of chemical reaction if its quantity is changed

passive transport

substances move according to their natural tendency without input of energy from the cell [no ATP]

Active transport

substance move froma region of higher concentration to a region of lower concentration against concentration gradient with the use of ATP molecules by the cell

Simple diffusion

net movememt of molecules from a region of higher concentration to aregion of lower concentration, down the concentration gradient

simple diffusion caused by? and results in?

random motion of atoms and molecules, equilibrium

factors affecting rate of diffusion

1. concentration gradient ( higher concentration, faster rate of diffusion)

2. distance over which difcusion occurs ( shorter the distance, faster rate of diffusion)

3. surface are to volume ratio ( larger SA to V ratio, faster rate of diffusion)

Channel proteins

hydrophilic channel, for ions and other hydrophilic molecules to enter and leave cell

Carrier proteins

substance binds temporarily to protein, changes the shape of the substance and transport it across the membrane

Osmosis

net movement of water molecules froma region of higher water potential to a region of lower water potential through a partially permeable membrane

bulk transport

transport of materials in and out of a cell by enclosing it within a vesicle

endocytosis

substance take in by inward folding of the cell membrane, forming a vesicle , ATP is used

exocytosis

secretory vesicle move towards and fuse with the cell membrane and releasing the contents of the vesicle into the fluid around the cell, ATP is used

respiration

process where glucose is broken down to realease energy, in the form of ATP in all living cells

aerobic respiration

the break down of glusose in presence of oxygen with the release of large amount of ATP molecules. carbon dioxide and water is released as waste products.

aerobic respiration

glucose + oxygen —> carbon dioxide + water + large amount of ATP

C6H12O6 + 6O2 —> 6CO2 + 6H2O

anaerobic respiration

the breakdown of glucose in the absence of oxygen, resulting in the release of lesser energy than aerobic respiration

aerobic respiration: alcoholic fermentation ( in yeast )

glucose —> ethanol + carbon dioxide + ATP ( small amount )

anaerobic respiration: lactic acid fermentation ( in human muscle cells )

glucose —> lactic acid + ATP ( small amount )