Life Processes At Cellular Level

Active Site

a region on an enzyme where the substrate binds with the enzyme and a chemical reaction occurs

Active Transport

movement of molecules from a low concentration to a high concentration (against the concentration gradient) that requires energy (ATP)

Respiration

process by which plants and animals break down glucose to release cellular energy (ATP) which is used to drive essential cellular processes

Anaerobic Respiration

Process of breaking down glucose to release energy without oxygen, resulting in few ATP molecules and lactic acid being produced

Catalyst

substance that speeds up the rate of a reaction, without taking part in it

Cell Membrane

phospholipid bilayer that controls what enters and exits the cell

cell wall

Rigid structure which provides support to cells, composed of cellulose in plant cells

Chloroplast

Organelle found in the cytoplasm of photosynthetic organisms which is the site of photosynthesis

Co-factors

molecules that complete the active site, allowing the substrate to fit

Concentration gradient

difference in the concentration of a substance from one location to another

Cristae

folds of the inner membrane of the mitochondrion that increase surface area for cellular respiration, enhancing ATP production

Denature

To alter the shape of a protein (enzyme) by breaking the bonds holding it together. This makes it unable to carry out its function.

Diffusion

net movement of particles from a region of high concentration to low concentration (down a concentration gradient) as a result of their random movement, until the concentration is equal, requiring no energy

Electron transport chain

series of proteins and electron carriers in the inner membrane of the mitochondria that produce around 34 ATP

Endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

Energy / ATP

Adenosine triphosphate is the energy carrier molecule in all living cells

Enzyme

protein, that has a specifc 3D shape due to its amino acid sequnce, that serves as a biological catalyst, breaking down or building molecules, allowing life to sustain

Exocytosis

process by which materials exist the cell by the vesicle fusing with the membrane to release substances outside the cell

Facilitated diffusion

larger or polar molecules can move freely across phospholipid bilayer from a high concentration to a low concentration using a specific protein channel, No energy required, (glucose, Na+ / K+)

Flaccid

not firm, cell lacking turgidity

Glycolysis

metabolic pathway that breaks down glucose into pyruvic acid, producing a net gain of 2 ATP, and occurs in the cytoplasm without requiring oxygen.

hypertonic solution

higher concentration of the solutes and lower concentration of water than that of the cell that resides in the solution

Hypotonic Solution (than that of in the cell)

lower concentration of solutes and higher concentration of water than that of the cell that resides in the solution

Competitive Inhibitor

substance that interferes with enzyme activity by binding to the active site, blocking the substrate from binding to the active site. So the reaction cannot proceed

Isotonic

solutions that contain the same concentration of solutes and water

Krebs cycle

a series of enzyme-catalysed reactions that occur in the mitochondria

Lysed

the breakdown of a cell due to damage done to the cell membrane

Matrix

fluid-filled space of the mitochondria. It contains enzymes, DNA, and ribosomes and is the site of the Krebs cycle

Mitochondria

Organelles which are the site of cellular respiration

Nucleus

membrane-enclosed organelle that contains DNA

Osmosis

net movement water molecules from a high concentration to a low concentration through a semi-permeable membrane, requiring no energy

Passive transport + Example

movement of molecules from a high concentration to a low concentration - simple diffusion,

Phagocytosis

A type of endocytosis in which a cell engulfs solids

Pinocytosis

a type of endocytosis in which the cell engulfs fluids

Organelle + example

a functionally and structurally distinct part of a cell (e.g ribosome)

Substrate

molecule which binds to the enzyme's active site, where it is converted into products.

Turgid

Firm; plant cells are swollen because they have absorbed water

Vacuole

organelle which stores food perserves/waste products

Water concentration / potential

proportion of a solution that is water

Cell

basic unit of all living organisms; surrounded by a cell surface membrane, contains genetic material and cytoplasm containing organelles

Simple Diffusion + Example

Small, non-polar molecules can move freely across the phospholipid bilayer from a high concentration to a low concentration, No energy required (O2, CO2)

Non-competitive Inhibitor + Example

substance that interferes with enzyme activity by binding somewhere else on the enzyme (not the active site), but changes the shape of the enzyme, so substrate cannot bind. So, the reaction cannot proceed + lead