Chapter 3a Flashcards
Structural units of living things
Cells have structure and function
How many cells does human body have
50 to 100 trillion cells
Activity of an organism depends on the collective
Activities of it’s cells
Principle of complementarity
Biochemical activities guided by their structure. Structure determines function
Continuity of life has a ____ basis
Cellular
Cells are ____ % water
60
Parts of cells
Nucleus
Cytoplasm
Plasma membrane
Cytoplasm
Liquid in cell
Regions in nucleus
Nuclear envelope (membrane)
Nucleolus
Chromatin
Nucleolus
Makes RNA
Ribosomes
Chromatin
Packaged DNA
Nuclear envelope
Barrier separates nucleus from outside
Has pores
Enclosed nucleoplasm
Nuclear pores
Let things into and out of nucleus
Function of ribosomes
Make proteins
Nucleus contains one or more dark staining ____
Nucleoli
____ is composed of DNA wound around histones (proteins)
Chromatin
_____ scattered throughout nucleus and present when the cell is not dividing
Chromatin
____ condensed to form dense, rod-like bodies called chromosomes when the cell divides
Chromatin
_____ _______Contains organelles
Plasma membrane
Fluid mosaic models
2 layers of phospholipids
Cholesterol and proteins
Sugar attached to phospholipids
Glycolipids
Sugar attached to phospholipids
Hydrophilic heads face
Outside of the layer (front and back)
Hydrophobic tails face
Inside of membrane
Can most water soluble molecules get through the cell membrane?
No, because the inside of the cell membrane is hydrophobic
Roles of proteins within plasma membrane
Enzymes
Receptors for hormones and other chemical messages
Transport channels and carriers
Glyproteins
Sugars attached to proteins that line the extracellular space
Glycocalyx
Fuzzy, sticky, sugar rich area on the cell’s surface
Allows cell attachment
How are cells bound together?
Glycoproteins
Wavy contours
Special membrane junctions
How are cells attached using glycoproteins?
Glycoproteins in glycocalyx act as glue
How do contours help attach cells?
Contours of adjacent cells fit together
How do membrane junctions help attach cells
They are formed depending on their roles
Tight junctions
Impermaneable
Leak proof sheets
Fuse like zipper
Desmosomes
Anchoring junction
Can’t be pulled apart by mechanical stress
Not impermaneable
What makes desmosomes
Button like thickenings of adjacent plasma membranes
Gap junctions
Communicating junctions
Connexons in between adjacent membranes
Molecules travel directly through the channels
Connexons
Hollow cylinders of proteins
Where is cytoplasm located?
Outside of nucleus and inside plasma membrane
Site of most cellular activity
Cytoplasm
Parts of cytoplasm
Cytosol
Inclusions and organelles
Cytosol
Fluid suspends nutrients and electrolytes
Inclusions
Chemical substances,
Stored nutrients or chemicals,
Cell products that float in cytosol
Organelles
Metabolic machinery of cell that performs function for cell
Organelles are usually surrounded by a
Membrane
Mitochondrial wall consists of
Double membrane with Cristae on inner membrane
Carries out reactions in which oxygen breaks down food into ATP molecules
Mitochondria
Cristae
Folding inner membrane of mitochondria
Ribosomes made of
Proteins and ribosomal RNA
Where can you find ribosomes?
Cytoplasm
Rough part of endoplasmic reticulum
Endoplasmic reticulum
Canals
Carry substances within cell
Make proteins
Where is the endoplasmic reticulum located?
Continuous with nuclear membrane
Rough ER
Makes proteins
Smooth ER
Detox
Synthesizes lipids
What gives rough ER it’s appearance?
It is studded with ribosomes
Transport vesicles
Move proteins within cell
What is abundant in cells that make and export proteins?
Rough ER
Examples of proteins made in rough ER
Antibodies and
Water soluble hormones
Steps for making and transporting proteins
- Made by ribosome
- Folds in tunnels. Sugars attached
- Packaged
- Transport vesicles buds off and goes to golgi apparatus
Smooth endoplasmic reticulum lacks
Ribosomes
What part of ER Functions in lipid metabolism
Smooth ER
Golgi apparatus
Postal service
Appears as stack of flattened membranes associated with tiny vesicles
Golgi apparatus
Modifies and packages proteins arriving from rough ER via transport vesicles
Golgi apparatus
Types of packages made by golgi apparatus
Secretory vesicles
In-house proteins and lipids
Lysosomes
Secretory vesicles
Pathway 1
Vesicle fuses with plasma membrane
excretes proteins into extracellular fluid
In house proteins and lipids
Pathway 2
Lysosomes
Pathway 3
Bags that have digestive enzymes
Exocytosis
Pouring out
Pathway 3 golgi vesicle containing digestive enzymes becomes a ___
Lysosome
What do lysosomes digest?
Worn out or unusable cell structures
Where are phagocytes housed?
Lysosomes
Phagocytes
Dispose of bacteria and cell debris
Peroxisomes
Detoxify alcohol and formaldehyde
How do peroxisomes detoxify?
Break down free radicals
Free radicals
Highly reactive chemicals
What are free radicals converted to?
Hydrogen peroxide and water
How so peroxisomes replicate?
Pinching in half or budding from endoplasmic reticulum
What do peroxisomes contain?
Oxidase enzymes
Cytoskeleton
Protein structures that gives shape
Types of elements that form cytoskeleton
Microfilaments
Intermediate filaments
Microtubules
Microfilaments (smallest)
Actin in muscle
Bat-like network
Machinery for intracellular transport
Cytoskeleton
Intermediate filaments
Keratin
Microtubules
Spindles during cell division
What are Centrioles made of?
Made of nine triplets of microtubules
Shape of centrioles
Rod shaped
Generates microtubules
Centrioles
Directs formation of mitotic spindle during cell division
Centrioles
Structure of cell membrane
Phospholipid bi layer with proteins and hormones embedded
Most externally facing proteins and lipids have sugar groups
Function of cell membrane
External cell barrier and acts in transport of substances
Maintains electrical condition that is essential for function of excitable cells
Function of cell membrane
Externally facing proteins act as receptors, transport proteins and help cells communicate within each other
Cell membrane function
Inclusions
Stored nutrients
Secretory products
Pigment granules
Cellular region between nucleus and plasma membranes
Cytoplasm
Structure of mitochondria
Rod-like double membrane structure
Inner membrane folded into Cristae
Function of mitochondria
Aerobic respiration
ATP synthesis
Powerhouse of the cell
Burning of glucose
Aerobic respiration
Structure of ribosomes
Dense particles consisting of two subunits,
Each composed of ribosomal RNA and protein
Free or attached to rough ER
Function of ribosomes
Sites of protein synthesis
Membranous system enclosing a cavity, the tunnel and coiling through the cytoplasm. Externally studded with ribosomes
Structure of rough ER
Function of rough ER
Sugar groups attached to proteins.
proteins bound in vesicles for transport to golgi apparatus
External face makes phospholipids
Membranous system of tunnels and sacs; free of ribosomes
Smooth ER structure
Site of lipid, steroid synthesis. Lipid metabolism, drug detoxification
Smooth ER function
Packages, modifies and segregates proteins for secretion from the cell, inclusion in lysosomes, or incorporation into the plasma membrane
Function of golgi apparatus
Stack of flattened membranes and associated vesicles close to ER
Golgi apparatus structure
Enzymes detoxify,
Most important breaks down hydrogen peroxide, catalase . Detoxify free radicals
Function of peroxisomes
Membranous sacs of oxidase and catalase enzymes
Structure of peroxisomes
Lysosomes structure
Membranous sacs containing acid hydrolase (powerful digestive enzymes)
Sites of intracellular digestion “stomach of the cell’
Function of lysosomes
Largest organelle
Nucleus
Surrounded by nuclear envelope
Contains nucleoplasm, nucleoli and chromatin
Structure of nucleus
Control center of cell; responsible for transmitting genetic info and info for protein synthesis
Function of nucleus
Double membrane with large pores. Outer membrane continuous with ER
Nuclear envelope structure
Separates nucleoplasm from cytoplasm. Regulates passage of substances to and from nucleus
Nuclear envelope function
Dense spherical (non membrane bounded bodies) composed of ribosomal RNA and proteins
Structure of nucleolus
Site of ribosome subunit manufacture
Function of nucleolus
Granular, threadlike material composed of DNA and histone proteins ‘beads on a string ‘
Structure of chromatin
DNA constitutes the genes, which carry instructions for building proteins
Function of chromatin
Surface entensions are found in
Some cells
Cilia
Move materials across cell surface
Move mucus
Flagella
Move cells
Think of sperm cells
Microvilli
Tiny extensions of plasma membrane
Increase surface area for absorbtion
Only flagellated cell in body
Sperm
Cell shape reflects it’s _____ function
Specialized
How many types of cells in human body
Over 200
Nerve cells are over 1 ___ in length
Yard
Some cells are 1/ 12,000 of an inch t/f?
True
Fibroblasts
Connect body parts
Secrete cable like fibers
Erythrocyte
Red blood cell
Carries O2
Connection cell
Cells that connect body parts
Fibroblasts
Red blood cells
Do erythrocytes have organelles?
No
Cells that cover and line organs
Epithelial cells
Packs together in sheets
Epithelial cells
What do the intermediate fibers do
Resist tearing during rubbing and pulling
True or false: epithelial cells can line organs like small intestine and esophagus and heart
True
Cells that move organs and body parts
Skeletal muscles and smooth muscle cells
Allow cells to shorten forcefully
Contractile filaments
Cells that store nutrients
Fat cells
Where are lipid droplets stored within fat cells
Cytoplasm
Cells that fight disease
White blood cells
Macrophages
Type of white blood cell
Phagocytic cell
Phagocytic cells
Absorb harmful cells or damaged cells
Digests infectious organisms
Macrophage
Cell that gather information and control body functions
Nerve cell (neuron)
Nerve cell
Receives and transmits messages to other body structures
Cells of reproduction
Oocyte (female)
Sperm(male)
Largest cell in the body
Oocyte
Divides to become embryo upon fertilization
Oocyte
Built for swimming to egg fertilization
Sperm
Abilities of cells
Metabolize
Digest food
Dispose of waste
Reproduce
Grow
Move
Respond to stimulus
Body’s main solvent is
Water
Intracellular fluid
Nucleoplasm
Cytosol
Solution containing gases, nutrients and salts dissolved in water
Intracellular fluid
Extracellular fluid is AKA
Interstitial fluid
Fluid on exterior of cell
Contains thousands of ingredients such as nutrients, hormones, neurotransmitters, salts and waste products
Extracellular fluid
Plasma membrane is selectively _____
Permeable
Modes of transport through plasma membrane
Passive
Active
Passive process
Substances transported without any input from the cell
Active transport
Requires ATP
Amino acids
Sugars
Ions
Uses pumps
Against gradients
Diffusion (passive)
High concentration to low concentration
Down concentration gradient
Particles distribute evenly within solution
Depends on particle size, charge and temp
Facilitated diffusion
Crossing through a protein without needing energy. Water
Uses carrier proteins but no energy
Primary Active transport
Against concentration gradient
Na and potassium
ATP
Secondary active transport
Moves against gradient
Uses downhill gradient from other to drive uphill movement.
Think piggybacking
When does diffusion happen?
Small enough to pass through pores
Lipid soluble
Assisted by membrane carrier
Simple diffusion
Lipid soluble
Or small enough
Osmosis
Simple diffusion of water through aquaporins
Moves down concentration gradient
Isotonic
Solute=water concentrations
No changes
Hypertonic
More solute than cells
Pulls water out of cells
Cells shrink
Hypotonic
Less solutes, more water than cell water moves into cells
Water moves towards
Area of higher solute concentration
Facilitated diffusion is used for
Lipid insoluble and large molecules
Glucose is transported via
Facilitated diffusion
Filtration
Water and solutes pushed by hydrostatic pressure
Pressure gradient or difference in pressure has to exist
Used by kidneys
Filtrate
Solute containing fluid
When are active transport processed used?
Too big
No carrier
Move against gradient
Not lipid soluble
Active transport example
Na(in) K (out)
Pump
Nerve impulses
Vesicular transport
Moving through vesicles in bulk
Endo and exocytosis
Mechanism used to actively secrete hormones, mucus and other products
Exocytosis
Docking
Proteins in vesicle recognize proteins in membrane and bind
Endocytosis
Extracellular substances are engulfed in membranous vesicle
Vesicle comes in and fuses with lysosome which digests
In some case vesicle will just be released
Phagocytosis
Cell eating
Bacteria or body cells
Pseudopods
Cytoplasm surrounds the bacteria or dead body cells from rest of environment
Phagocytosis
Protective mechanism,
Not a means of getting nutrients
Pinocytosis
Cell drinking
Gets proteins or fats from extracellular fluid
Routine for absorbtion cells like small intestine
Fluids and small solutes
What does plasma membrane do during pinocytosis?
Forms a pit. Edges fuse around the droplet or fluid
Contains digestive enzymes of many varieties; can destroy the entire cell
Lysosomes
Slender extensions of the plasma membrane that increase it’s surface area
Microvilli
Stored glycogen granules, crystals, pigments
Inclusions
Two rod shaped bodies near the nucleus; the basis of cilia
Centrioles
Contractile elements of the cytoskeleton
Microfilaments
Site of detoxification of alcohol, hydrogen peroxide and harmful chemicals
Peroxisomes