Cell Structure Flashcards
Procaryotic Cell
Contains membrane & cytoplasm - no nucleus or membrane bound organelles
Eucaryotic Cell
Contains cell membrane that separates contents inside cell from contents outside cell. Contains nucleus & cytoplasm
What is in cytoplasm?
Lots of organelles that contribute to cell function
What protects the cell membrane against mechanical damage and why?
Glycocalyx - produced by glycoproteins & glycolipids which is formed when CHO attach to proteins & lipids. It is important the body can identify what is “self” / what is foreign
Erythrocytes
Red blood cells
Leukocytes
White blood cells
Tissues
Group of cells that share similarities are classified into tissues
Cell functions
Reproduction, differentiation - being able to determine what is self and what isn’t, protein synthesis - manufacture of proteins
What do you need to enable the cell to function?
A balanced of electrolytes/molecules across cell, wastes need to be removed, nutrients need to be received & maintained, communication (cells need to be told what to do)
Cell membrane structure
2 fatty layers of phospholipids. Heads are hydrophilic & tails are hydrophobic
What are cell membranes important?
Ensure a barrier to the cell. Barrier can decide what goes into cell & what leaves. Cell is selectively permeable
What are gated channels?
They open specially to let something pass. Often a reaction between internal cell and external cell which helps open channels
Carrier protein
Attaches to molecules; helps molecules cross membrane
Receptor
Marker on cell membrane which indentifies to the cell that something needs to cross membrane, this opens the channels (e.g. insulin unlocks to let glucose in)
Projections
Finger like extensions that move from the membrane outward
Microvilli
Found in the small intestine & skin where absorption is essential
Cilia
Hair like extensions that move, pushing contaminated substances along a surface (e.g. moving mucous out of nose)
Flagella
Long extensions that allow the cell to swim (sperm)
Exocytosis
Transporting materials from ICF to ECF (moving out) usually enclosed in a vesicle
Endocytosis
Transporting material from ECF to ICF (moving in) to contribute to cells survival (glucose)
Phagocytosis
Happens when a cell is trying to destroy something (virus) - large vesicles
Pinocytosis
Cell takes in ECF along with small dissolved molecules - via small vesicles
Receptor-mediated endocytosis
Uses special receptor proteins to help carry large particles across cell membrane - Aquire nutrients
What is a “lock and key” response?
When a particular substance finds the connecting cell receptor & binds together for a response to occur
