Cell structure and transport Flashcards
What is cytoplasm?
Watery material inside cell that fills space between nucleus and membrane
-cytosol
-organelles
Function of the cell membrane
-cell boundary/barrier
-helps support the cell
-controls what substances can enter or exit the cell
-sensitive to change
Function of the cytosol
liquid part of cytoplasm
-most metabolic reaction occur here and controls osmotic pressure
-and the flow of chemicals in and out of cell
Function of the nucleus
-stores information and instructions (DNA)
-controls chemical reactions within cytoplasm
Functions of the ribosome
-line the rough endoplasmic reticulum
-construct proteins out of amino acids
Function of endoplasmic reticulum (rough and smooth)
rough:
-transport proteins around the cell
smooth:
-involved in the manufacture of lipids and fast
Both provide SA for chemical reactions
Function of the Golgi body
-near nucleus
-package proteins, lipids, carbs into vesicles
-export it from the cell which later produces lysosomes
Function of lysosomes
-contains digestive enzymes
-can be secreted or used to destroy ingested foreign material
-can also self-destruct the cell (apoptosis)
Function of the mitochondria
-converts nutrients into usable energy
e.g. glucose
-powerhouse of the cell
Function of the centriole
-aids in cell division
-arrange microtubules
What is cilia?
-Hair like projections on the outer layering of cells
-beat rhythmically to allow movement of materials across said cell
Functions of cytoskeleton
-framework of protein fibres
-give cell it’s shape
-assists in cell movement
What is homeostasis?
-maintenance of relatively constant internal environment
-despite fluctuations in the external environment of a cell
Functions of the cell membrane
Define active transport
-movement of ions/molecules against a concentration gradient
- low conc. to high
-assisted by enzymes requiring energy (ATP)
Define passive transport
-movement of materials across cell membrane
-no energy required
What is concentration/diffusion gradient
A difference in the concentration of a substance across a distance
Define simple diffusion
-movement of a solute along a concentration gradient
-area of high conc. to low conc.
-spreading out of particles to create even distribution over the provided space
e.g. breathing (gas exchange)
Define osmosis
-diffusion of water molecules
-across a semi-permeable membrane
-dilution
e.g. nutrient absorption in large + small intestines
Define facilitated diffusion
-diffusion of solutes where transport proteins allow for movement across a membrane
-passive because the solute moves along a gradient (high conc to low)
-aids large molecules in going through the membrane
What are protein channels?
-proteins embedded in the phospholipid bilayer
-help large molecules pass through
What is carrier mediated transport?
-solute binds to a carrier in plasma membrane
-membrane shapes around it
=solute is released in other side of cell
e.g. facilitated diffusion, active transport
What is vesicular transport?
-movement of substances across cell membrane in vesicles (absorb around substance)
-then absorbed into membrane and pushed to inner or outer cell
-uses energy to create vesicles
e.g. endocytosis and exocytosis
What is endocytosis? and two types?
Taking in on solutes into the membrane
-pinocytosis=taking liquids
-phagocytosis=taking in solids
What is exocytosis?
Expelling of solutes through the vesicles
Substances and their transportation methods
Simple diffusion: oxygen, carbon dioxide, water, alcohol, fatty acids, sodium, calcium, lipids
Osmosis: water
Facilitated diffusion: glucose, amino acids
Active transport: glucose, ions, amino acids
Function of microtubules
-maintain cell shape
-guide organelle movement
Why are cells small?
-being smaller allows for a higher SA:V
-absorbs more nutrients and works more efficiently
What are body’s structural levels
Cells, tissues, organs, organ systems
What are the tissues?
-epithelial
-connective
-muscular
-nervous
Function of epithelial tissues
Made up of closely joined cells and are varying shapes. Covers
inner: heart, kidneys, intestines, liver, lungs
outer: stomach, heart, intestines
-depending on location, protects, secretes and absorbs
Function of connective tissues
-provides support to the body
-holds together all of its parts
made up of separated cells divided by non-cellular matric
e.g. bone, cartilage, tendons, ligaments
Function of nervous tissue
-made up of neurons
-neurons carry messages to different parts of the body
e.g. brain, spinal cord, nerves
Function of muscle tissues and the types
Smooth:
Walls of stomach and intestines, blood vessels, iris
-involuntary
-non-striated
Skeletal:
Muscle attached to the bone
-voluntary control
-stripes (striated)
Cardiac:
Most of heart (contracts to pump blood)
-non-voluntary
What is the fluid mosaic model?
Model of the cell membrane. Includes
-hydrophilic heads
-hydrophobic tails
-phospholipid bilayer
-cholesterol and protein embedded in bilayer
