9/25-30 Cell Structure and Function

Cells are made of

biomolecules

After the invention of microscopes in the 1590s,

cells were discovered and cell theory was soon(ishly) developed

Robert Hooke (1665) said

cells exist

Anton Leeuwenhoek (1674) said 

unicellular organisms exist 

Matthias Schleiden (1838) said

plants are made of cells

All living cells arise by division of

pre-existing cells

Cells contain 

hereditary material, which they pass to their offspring for their division 

Cells are still studied with microscopes, more recently with

electron microscopes and fluorescent microscopy

Cell parts are also isolated and examined by

cell fractionation using centrifuges

the biggest organelle is the

nucleus

All cells are made of

plasma membrane, cytosol/cytoplasm, genetic material (chromosomes), and ribosomes

On the outside of a prokaryotes are 

Capsules, Cell Wall, Plasma Membrane, Pili, and Flagella

Capsules

sticky layer that helps prokaryotes stick to surfaces, some capsules add extra protection

Cell Wall

Supports cell shape, protects cell, permeable to water (so dissolved stuffed can cross into cell)

Plasma Membrane 

Phospholipid Bilayer 

Pili

some prokaryotes have these, they help the bacterium stick to surfaces. Other types of pili can be used to “spear and reel in” other bacteria to exchange plasmid DNA

Flagella

Used for motion, whips around like a propellor

The organelles in the inside of Prokaryotes are

Ribosomes, Plasmids, and Nucleoids

Ribosomes are __ and __

Free floating, makes proteins 

Plasmids

Small circular chunks of DNA that contain a couple of genes that are easily shared with other bacteria

Nucleoid

One large circular chunk of DNA. Contains rest of the bacteria’s genes. Not enclosed by a nucleus

Bacteria cell walls are made of

peptidoglycan

Plasmid is smaller DNA compared to the 

Nucleoid DNA 

Eukaryotic cells have internal membranes that

compartmentalize their functions (organelles), isolate specialized environments (pH, molecules), and to increase internal surface area for reactions

Eukaryotic cells are either __ (plant-like) __ (animal like)

photo-autotrophic or chemo-trophic 

Cell structures/functions vary among tissues and organs of multicellular organisms due to

cell differentiation

The ___ efficiently coordinates the sending of ___ from ___ to their destinations 

endomembrane, proteins, and ribosomes

The nucleolus, E.R, the Rough E.R, the Smooth E.R, and Golgi apparatus compose the

endomembrane system

Nucleolus

Compartment of nucleus that makes ribosomes

Red blood cells (RBCs)

kick out their nucleus during development to make room for hemoglobin

___ are the side of ___ for ___. This is where proteins are assembled from amino acid monomers

Ribosomes, translation, and protein synthesis

___ make cytoplasmic proteins, but ___ on the ___ make membrane and excretory proteins. Bound ribosomes are in eukaryotic cells only

Free ribosomes, bound ribosomes, and Rough E.R 

The ___ compartmentalizes the cell for protein synthesis, since it has bound ribosomes on its surface

Rough E.R

Proteins made by rough ER travel to ___ to be packaged into vesicles and sent away to the golgi apparatus. Other proteins stay in the smooth E.R to become enzymes that break down macromolecules or poisons (detoxification). The smooth ER also makes phospholipids for cell membranes 

Smooth E.R

small membranous sacs that store materials or transport/secrete materials around/out of cells

Vesicles  

___ are larger vesicles that function as storage for food, water, or waste

Vacuoles

___ are in unicellular eukaryotes, like in paramecium, this is used to dispel excess water. 

Contractile Vacuoles 

Lysosomes are produced by the

golgi apparatus

Mitochondria

Eukaryotic organelle that makes the energy molecule ATP through aerobic respiration (meaning oxygen is need…this is why we breathe in!!!)

Chloroplasts

Function in photosynthesis in plants and algae

Plants have ___ and ___ while animals just have ___

Mitochondria, chloroplasts, and mitochondria

Chloroplasts are considered

plastids

plastids are organelles that contain

pigments surrounded by a membrane. Plastids have their own DNA and ribosomes 

Chloroplasts, other plastids, and mitochondria are theorized to be a part of eukaryotic cells by the

Endosymbiotic Theory

What is the evidence of Endosymbiotic Theory?

The membranes are very similar by size, binary fission is happening, mitochondria do that. The DNA of mitochondria and chloroplasts show that there are many significant portions between chemo-trophic and auto-phototrophic DNA.

Mitochondrial DNA is

maternal DNA

Nuclear DNA is the

paternal DNA

Animals have an ___, networks of connective proteins (like collagen) outside the cell membrane

Extracellular Matrix (ECM) 

In plants, ___ are passageways in the cell walls, connecting the cytoplasms of adjacent cells to allow communication

Plasmodesmata