Transport Across The Cell Membrane Flashcards
The cell membrane is also know as the
Plasmid membrane
Membranes age extremely thin and are made of
Phospholipids and proteins
The lipids form two layers called a blank of molecules which are blank
Fill in the blanks
Bilayer
Mobile
The arrangement of proteins are found scattered as a
Mosaic
The phospholipid layers can move around the membrane so are said to be
Fluid
The membrane is described as
Fluid-mosaic
The cell membrane is selectively permeable which means
Not all molecules can pass through it
Small molecules can pass through easily
Give three examples of small molecules
Oxygen, carbon dioxide and water
Larger molecules can pass through slowly
Give two examples
Glucose and amino acids
Very large molecules can’t pass through at all
Give two examples
Protein and starch (in plants)
Small molecules pass through the selectively permeable membrane in three ways. Name them
1) Diffusion
2) Osmosis
3) Active transport
1&2 = passive processes; don't require energy 3 = not passive; does require energy
Diffusion is the movement of molecules from a region of blank concentration to a region of blank concentration until the concentration becomes blank
Fill in the blanks
High
Low
Equal
Molecules always diffuse blank a concentration blank
Fill in the blanks
Down
Gradient
Respiration in the cell uses oxygen and produces what?
Carbon dioxide
If carbon dioxide builds up in a cell it becomes
Toxic/poisonous
It is vital the carbon dioxide diffuses blank of cells
Out
Diffusion occurs in the
Lungs, the tissue and the digestive system
In the digestive system blank molecules eg blank are broken down in to blank molecules eg glucose. The small molecules move front the digestive system into the blank through the blank
Fill in the blanks
Large Starch Small Blood Cell membrane
Starch will turn iodine solution from
Brown to black/blue
Glucose will turn the Clinistix from
Pink to purple
Osmosis is a special type of
Diffusion
Osmosis is the movement of blank from a region of high blank concentration to a region of low blank through a selectively permeable membrane
Fill in the blanks
Water molecules
High
Low
Osmosis is a
Passive process
Water molecules diffuse from a high water concentration to a region of low water concentration through the
Pores in the membrane
Animal cells shrink when
Water has moved from hwc to lex
Animal cells burst when
Water has moved into the cell
A plant cell has plasmolysed when
Water moves from HWC to LWC
A plant cell is turgid when
The water has moved from HWC to LWC
Active transport is the process by which dissolved molecules and ions move across a cell membrane from
A low to high concentration
In active transport particles move against a concentration gradient and therefore
Require an input of energy from the cell
Cells that carry out active transport have
Many mitochondria
What picks up specific molecules and takes them through the cell membrane against the concentration gradient?
Carrier proteins
A carrier molecule actively pumps what out of the cell and what into the cell against its concentration gradient?
Sodium ions & potassium ions
