Module 2 Cells Flashcards
What is the cell Theory
All cells come from the division of preexisting cells, cells are the smallest unit of life, each cell maintains homeostasis at the cellular level
Procaryotes
Bacteria, single chromosomes, no nucleus or organelles
Eukaryotes
Plant and animal cells
Erythrocyte
Red blood cell
Leucocyte
White blood cell
Lymphocyte
A cell of the lymph system
Monocyte
A type of white blood cell
Osteocyte
A bone cell
Keratinocytes
A type of skin cell
Phagocyte
A cell that engulfs foreign material or debris
Erythroblast
Immature red blood cell
Osteoblast
Immature bone cell
Monoblast
Immature monocyte
Haemocytoblasts
Immature blood cell
Functions of centrosome and centrioles
Essential for movement of chromosomes during cell division; organisation of microtubules in cytoskeleton
Functions of cytoskeleton
Strength and support; movement of cellar structures and materials
Function of plasma membrane
Isolation, protection, sensitivity, support, controls entry and exit of materials
What makes up the phospholipid bilayer
Hydrophilic heads, hydrophobic fatty-acids tails, barrier to ions and waters
What’s interstitial fluid
Extracellular fluid is a watery medium that surrounds a cell
What’s cytoplasm
Fluid inside the cell (cytosol = liquid), contains intracellular structures collectively known as organelles
What does cytosol contain
Dissolved nutrients, ions, proteins and waste products
List 6 nonmembranous organelles
Cytoskeleton, microvilli, centrioles, cilia, ribosomes and proteasomes - direct contact with cytosol
List 5 membranous organelles
Endoplasmic reticulum, the Golgi apparatus, lysosomes, peroxisomes and mitochondria
What three things make up the cytoskeleton
Microfilaments, intermediate filaments, microtubules
What are microfilaments
Thin filaments composed of the protein actin that provide strength, interact with proteins, pair with thick filaments of myosin for muscle movement
What are microtubules
Large, hollow tubes of Tubulin
What do microtubules do
Attach to centrosome, strengthen cell and anchor organelles, change cell shape, move vesicles within cell, form spindle apparatus
Function of microvilli
Increase surface area and absorption and attach to cytoskeleton
Functions of centrioles in the Centrosome
Centrioles form spindle apparatus during cell division, centrosomes cyotoplasm surrounding centriole
Function of cilia
Small hair like extensions that move fluids across the cell surface
Function of ribosomes
Build polypeptides in protein synthesis
Function and location of free ribosomes
In cytoplasm, manufacture proteins for cell
What is the function and location of fixed ribosomes
Attached to ER, manufacture proteins for secretion
What are proteasomes
They contain enzymes which disassemble damaged proteins for recycling
What is the endoplasmic reticulum attached to
Cisternae - storage chambers within membranes
Functions of endoplasmic reticulum
Synthesis proteins, stores synthesised molecules and materials, transport of materials within the ER, detoxification of drugs or toxins
Functions of the Golgi body
Modifies and packages secretions (hormones or enzymes), renews or modifies the plasma membrane, packages special enzymes within vesicles for use in the cytoplasm
Functions of lysosomes
Clean up inside cells (autolysis), break down large molecules, attack bacteria, recycle damaged organelles, eject waste by exocytosis
What is autolysis
Self destruction of damaged cells
Function of mitochondria
Takes chemical energy from glucose to form ATP
Aerobic metabolism / cellular respiration equation
Glucose + O2 + ADP -> CO2 + H2O + ATP
What is the nucleus
The control centre of the cell
What surrounds the nucleus
Nuclear envelope
What is the space between the two layers of the nuclear envelope called
Perinuclear space
What’s the function of nuclear pores
Allow communication to outside the nucleus
What are nucleoli made of and what do they do
Made of RNA, enzymes and histones, synthesise rRNA and ribosomal subunits
What are nucleosomes
The DNA coiled around histones
What are chromatin
Loosely coiled DNA (cells not dividing)
What are Chromosomes
Tightly coiled DNA that divides
What is selective permeability based on
Size, charge, shape, lipid solubility
Is diffusion active or passive
Passive
Is carrier mediated transport active or passive
Can be either
Is vesicular transport active or passive
Active
Five factors that influence diffusion
Distances, molecule size (smaller is faster), temp (higher temp = faster), conc. gradient, electrical forces i.e opposites attract
What two types of materials diffuse through the plasma membrane via simple diffusion
Lipid-soluble compounds, dissolved gases
What uses channel-mediate diffusion
Water-soluble compounds and ions
What is osmosis
The diffusion of water across the cell membrane
In osmosis which side does the volume increase on
The side with More solutes
Which direction do water molecules diffuses in during osmosis
Low to high SOLUTE concentration
What must the membrane be during osmosis
Freely permeable to water, selectively permeable to solutes
Define osmotic pressure
The force of s concentration gradient of water
What can prevent osmosis
By an applied force that is equal to the amount of hydrostatic pressure required to stop the osmotic flow
Isotonic define
A solution that does not cause osmotic flow of water in or out of a cell (equal concentrations)
Hypotonic define
Has less solutes and loses water through osmosis
Hypertonic define
Has more solutes and gains water by osmosis
Two fluids may have equal …. But different …
Osmolarity, tonicity
What happens to a cell in a HYPOTONIC solution
Gains water and ruptures, i.e hemolysis of red blood cells
What happens to a cell in a HYPERTONIC solution
Loses water, shrinks i.e cremation of red blood cells
What is cotransport in relation to carrier mediated transport
Two substances move in the same direction at the same time
What is countertransport in relation to carried mediated transport
One substances moves in while another moves out
What is facilitated diffusion
Passive process where carrier proteins transport molecules too large to fit through channel proteins (glucose, amino acids)
Two steps of facilitated diffusion
Molecule binds to receptor site on carrier protein,
protein changes shape and molecule passes through,
What is active transport
Process that requires energy to move substrates against the concentration gradient
What do ion pumps move
Ions such as Na+, K+, Ca2+, Mg2+,
What are exchange pumps
Pumps that countertransport two ions at the same time
Example of primary active transport
Sodium-potassium exchange pump, pumps sodium ions out and potassium ions in, 1 ATP moves 3 Na+ and 2K+
Example of secondary active transport
Na+ concentration gradient drives glucose transport and ATP pumps Na+ back out
What is vesicular transport
Movement where materials move into or out of cell in vesicles
Two types of endocytosis
Pinocytosis (drinking), phagocytosis (eating )
How does endocytosis work
Receptors (glycoproteins) bind target molecules (ligands) and coated vesicles (endosome) carry ligands and receptors into the cell
What is exocytosis
Granules or droplets are released from the cell
