Module Two Flashcards
Describe the structure of the plasma membrane
It determines IF and HOW substances move in and out of the cell
Hydrophilic heads
Hydrophobic tails
Double layer
The 2 proteins on plasma membrane
Integral proteins vs peripheral proteins
Integral - embedded within the lipid bolster
- channels for substances that cannot pass through the bilayer
Peripheral- not embedded/ attached to integral or float around
Cell membrane support
What can lipid soluble substances do
Can pass through the membrane
Oxygen, carbon dioxide etc
Integral proteins
Substances that are too large or lipid insoluble use them
They are substance specific
Transport of water
It can freely cross through the plasma membrane even though it is lipid insoluble
Can also use a protein channel called aquaporins
What are the two types of transport
Active and passive
Passive requires no energy - simple and facilitated diffusion. Osmosis
Active requires atp
Primarily active transport
Simple diffusion
Down the concentration gradient
Continues until equilibrium
Facilitated diffusion
Uses integral proteins
Down the concentration gradient
Uses leakage and gated channels
Osmosis
Net diffusion of water through the selectivity permeable membrane
Down concentration gradient
Active transport
Needs atp
Endocytosis vs exocytosis
Particles that are too large to move across the membrane by diffusion
End- entering
Ex- exiting
Isotonic - hypertonic - hypotonic
Isotonic- same concentration as cell
No change in cell volume or shape
Hypertonic - cell shrinks
Low water high solutes
Hypotonic- cell gets larger and can burst/ lyse
Low concentration high water
Resting membrane potential
It is the voltage that exists across the plasma membrane
Generated by difference in sodium and potassium ion concentrations between the ecf and the icf
Maintained by the active transport of ions using the carrier protein called the Na/K ATPase pump
Environment around the plasma membrane
Na is higher in ECF
K is higher inside the cell
Organelles
Cytoplasm
Cellular material between the plasma membrane and the nucleus
Includes cytosol, icf, organelles in the fluid
Organelles
Nucleus
Largest organelle
Contains DNA
All mature cells except rbc have them
Cells need them to reproduce
Mitochondria
Break down nutrients from the foods we eat and convert that energy into atp (cellular respiration)
Highly active cells like muscle cells will have a lot of mitochondria
Ribosomes
Site of protein synthesis
There are free ribosomes and membrane bound ribosomes
Endoplasmic reticulum
Rough vs smooth
Rough-
Has ribosomes studded on the membrane
Proteins are synthesis and packaged
High in liver cells
Smooth
Synthesis of lipids cholesterol phospholipids and steroids
High in testes
Golgi apparatus
Modify package and distribute proteins and lipids produced in the cell
Lysosomes
Contains digestive enzymes that can digest invading bacteria viruses toxins dead cells and old organelles
High in white blood cells
What are the three organelles involved in protein synthesis
Ribosomes, rough er, Golgi apparatus
Which organelle is a sac of enzymes involved in digestion
Lysosomes
Which organelle packages proteins
Golgi apparatus
What is composed of the contractile protein chain
Microfilament
Protein synthesis process
DNA provides instructions for building every protein in the body
RNA carries out orders for protein synthesis
4 types of tissues in the body
Connective
Nervous
Muscle
Epithelial
Nervous tissue
Internal communication
- brain
- spinal cord
- nerves
Muscle tissue
Conscious
Contracts to cause movement
Muscles attached to bones (skeletal)
Muscles of heart (cardiac)
Muscles of walls or hollow organs (smooth)
Epithelial tissue
Forms boundaries between different environments, protects, secrets, absorbs, filters
Lining of digestive tract organs and other hollow organs
Skin surface (epidermis)
Connective tissue
Supports, protects, binds other tissues together
Bones
Tendons
Fat and other soft padding tissue
Skin contains the four primary tissues- where are they
- epithelial tissue- epidermis
- connective tissue - dermis
- smooth muscle tissue- arterioles and attached to hair
- nervous tissue- sensory nerves
SKIN
Largest and heaviest organ
Part of the integumentary system “covering”
Skin has 2 layers
Epidermis = outer epithelial layer
Dermis = a deep supporting layer of dense connective tissue
What is the hypodermis
Layer below the skin composed of loose connective tissue and fat
Epidermis
Lacks blood vessels
Dynamic steady state- cells constantly dying
Constant renewal of cells - epidermis is replaced every 25-45 days
5 epidermal layers (called strata) because cells are constantly moving to the superficial layer (and eventually dying)
5 epidermal layers/ strata
Stratum corneum (most superficial layer)
Stratum lucidum
Strata granulosum
Strata spinosum
Strata basale (deepest layer)
5 cells of the epidermis
Stem cells ( divide)
Keratinocye- produced keratin
Melanocytes - produce melanin
Merkel cells - touch receptors
Langerhans s - activate immune responses
