Chapter 7: Inside the Cell (Final)

Bio 205 (146 – 161, skip 7.5 and 7.6)

Cytoplasm

all contents inside of cell membrane, including organelles but no the nucleus 

Genes

located on chromosomes, specific segments of DNA (or a sequence of nucleotides) that contain hereditary information for building functional RNA’s

nucleoid

region within the prokaryotic cell that contains all or most of the genetic material

Chromosomes

threadlike structure of DNA and protein that carry genetic information

Plasmids

small, usually circular, supercoiled DNA molecules. Different than chromosomes, help to adapt under unusual circumstances 

Ribosomes

molecular machines that are responsible for protein synthesis/translating RNA (2nd part of the central dogma)

Scattered in cytosol in the millions

composed of large and small subunits, each of which contains RNA (stores info to synthesis proteins) and protein molecules

Cytoskeleton

web of protein filaments which provide structural support, helps with cell movement, and facilitates the transport of organelles

actin filaments, intermediate filaments, and microtubules

Organelles

internal compartments in cells with enzymes or structures for  specialized tasks, often bound by membrane 

EX) nuclear envelope, endoplasmic reticulum, and Golgi apparatus

Nucleus

membrane bound compartment where where eukaryotic chromosomes are enclosed

Enclosed in unique double-membrane structure called the nuclear envelope

endoplasmic reticulum

A portion of the nuclear envelope extends to a cytoplasmic membrane-enclosed factory (organelle). involved in protein and lipid synthesis

has two parts

Rough ER (RER): Lined by knobby-looking ribosomes for protein production 

Smooth ER (SER): Involved in lipid synthesis, detoxification, and calcium storage

Lumen

interior if any sac-like structure in cell / body

Golgi apparatus

stack of membranous sacks called cisternae that process, sort, and packag proteins and lipids into vesicles

Proteins that leave the RER go into the golgi apparatus 

1. Cis: closest to nucleus  

2. Trans: surface oriented toward plasma membrane 

Lysosomes

contain digestive enzymes enclosed in a single membrane that help with breaking down worn-out cell parts and killing viruses/bacteria

digestion and recycling centers, part of the endomembrane system

Peroxisomes

globular organelles, centers for reduction-oxidation reactions with fatty acids/ethonal/etc. which detoxify reactive molecules

mitochondria

Makes adenosine triphosphate (ATP) with carbs and fats, which stores the chemical energy needed to maintain structure and function of cell

Has two membranes, inner (saclike series of cristae) and outer (cell surface)

solution enclosed within the inner membrane is called the mitochondrial matrix

chloroplast

double membrane plus membrane-bound sacs

production and sugars via photosynthesis 

1. Surrounded by double membrane with a third membrane inside that forms flatten-sac-like structures called thylakoids

2. Arranged in connected stacks called grana 

3. Stroma: fluid-filled space in between the grana, which contain enzymes that use chemical energy to produce sugars 

cytoskeleton

actin filaments

intermediate filaments

microtubules 

structural support, movement of materials or cell

plasma membrane

protects the interior of a cell from the outside environment

phospholipid bilayer with transport and receptor proteins

has selective permeability

cell wall

outer layer outside the cell membrane

fibers running through carbs or protein matrix

protection, structural support

ONLY IN PLANT CELLS

Vacuoles

membrane-bound comparements in cells that store carbs, water, pigments, oils, toxins, or hydrolases

storage, digestion, recycling 

Phospholipid Bilayers

thin polar membrane made of two layers of lipid molecules

Phospholipids have hydrophilic phosphate head and a hydrophobic tail consisting of two fatty acid chains

All Cells have

• a plasma membrane, which is the outer layer that separates the cell’s interior from its surrounding environment;

• cytoplasm, which consists of the jelly-like cytosol inside the cell, plus the cellular structures suspended in it;

• genetic material in the form of DNA; and

• ribosomes, which are structures that build the cell’s proteins.

eukaryotic

membrane-bound organelles like a nucleus

are larger

Eukaryotes include both unicellular and multicellular organisms. Multicellular eukaryotes are made up of many eukaryotic cells

Prokaryotic

lack membrane-bound organelles. 

have nucleoid, a region in the cell where the genetic material is located

genetic material typ. located in circular chromosomes 

typically unicellular organisms but can live in groups