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