Chapter 7 Cells Flashcards
Robert Hooke
England 1665
Looked at cork, saw many empty chambers and called the cells
Anton von Leeuwenhoek
Holland- around 1665
observed living organisms under a microscope
Matthias Schleiden
botanist, all plants are made of cells
Theodore Schwann
biologist, all animals are made of cells
Rudolf Virchow
physician, new cells can be produced from the division of other cells
Cell Theory
- all living things are made of cells
- cells are the basic unit of structure and function in living things
- new cells are produced from existing cells
Compound light microscope
Light passes through an organism and uses 2 lenses
- objective lens
- ocular lens
Compound light microscope limitations
- resolution of the image
- only magnification of 1000x
- need to use stains or dyes for most cells
Electron microscopes
use electrons focused by a magnetic field instead of light
higher resolution
transmission electron microscopes
- electrons travel straight through a specimen
- used to see cell structures and protein molecules
- images are 2-D
Scanning electron microscopes
- Electrons scan the surface of the specimen
- Images are 3-D
all cells contain…
DNA
DNA
biological molecule that carries information
all cells are surrounded by…
cell membrane (plasma membrane)
Prokaryotes
- smaller in size
- simple structure
- no nucleus
- example: bacteria
Eukaryotes
- larger in size
- complex structure
- contain many structures (organelles)
- specialized membranes
Nucleus and cytoplasm work together to…
help a cell function
Nucleus description
- surrounded by a double membrane called a nuclear envelope or nuclear membrane
- shape is maintained by skeleton called a nuclear matrix
- filled with fluid known as nucleoplasm
Nucleus location and size
Location- in the cytosol
Size- most prominent structure
- double membrane called nuclear envelope
- shape is maintained by a skeleton called nuclear matrix
- filled with fluid known as nucleoplasm
Nucleus function
STORE HEREDITARY INFORMATION
chromotin
- Combination of DNA and proteins
- Coils up to chromosomes for cell division
Nucleolus
- synthesis of ribosomes
- concentrated DNA when making ribosomal RNA (rRNA)
Vacuoles
- large, saclike, membrane enclosed structures
- some cells have one central vacuole and others have many smaller ones
Vacuoles function
store water, salt, proteins and carbohydrates
Vesicles
smaller membrane enclosed structures
Vesicles function
store and move materials between or to and from cell organelles
Lysosomes
- made by Golgi
- contain digestive enzymes
- involved in embryonic development
Lysosomes function
- breakdown proteins, nucleus acids, carbohydrates, and lipids
- digest old cells (autolysis) or old organelles (autophagy)
Cytoskeleton location and size
Location- within the cytosol
Size-spans the entire length of cell (provides a framework)
Cytoskeleton function
- provide structure to maintain shape and size
- participates in movement of organelles in the cytosol
Microfilaments
chains of actin (protein) molecules
-cell movement and contraction of muscle cells
Microtubules
- made of tubulin (protein)
- extend from central point
- from spindle fiber and centrioles during cell division
- from cilla and flagella for movement of cells
Ribosomes description
- made in nucleolus, completed in cytoplasm
- no membrane around it- evolution (pro cells)
Ribosomes location and size
Location- scattered throughout the cytosol or attached to endoplasmic reticulum
Size- relatively small and most numerous
(made of RNA and protein)
Ribosomes function
protein synthesis
Endoplasmic Reticulum location
within the cytosol, sometimes attached to the nucleus
Endoplasmic reticulum function
Intracellular highway- a path for molecules to move from one part to another
Endoplasmic reticulum description
cisternae- membrane tubes and sacs
Rough ER
- produces phospholipids and proteins
- prominent in cells that export large amounts of proteins from the cell or used in cell’s own membranes
Smooth ER
- synthesis of lipids (cholesterol)
- synthesis of steroids (hormones) in glands
- regulate calcium levels in muscles (heart and skeletal)
- breakdown toxic substances (drug/alcohol) in liver cells
difference between rough and smooth ER
Rough ER has ribosomes
Golgi Bodies location and appearance
Location- within the cytosol
Appearance- system of membranes; series of flattened sacs
Golgi Body function
works with the ER to modify proteins for transport from cell
(adding a carbohydrate or lipid to the protein ect.)
Chloroplasts
organelle with a double membrane (contains DNA)
- system of thylakoids (flattened membranes) in stacks (grams)
- contain chlorophyll- pigment that captures light energy
Chloroplast function
- capture energy from light and convert it into food that contains chemical energy
- site of photosynthesis
Chloroplasts location
Location- within the cytosol
Mitochondria location and size
Location- scattered throughout the cytosol
Size-relatively large
Mitochondria function
- site of chemical reactions that transfer energy from organic compound to ATP
- responsible for producing 95% of energy for a cell to function
2 mitochondria membranes
Outer- serves as a boundary between mitochondria and cytosol
Inner- long folds called cristae, which increases surface area for chemical reactions to take place
Mitochondria DNA
- can produce on their own
- only get it from your mom
- theory of endosymbiosis
