Biology Chapter 4

ribosomes

cells proteins synthesis, synthesized in cucleolus, cells that synthesize large amounts of proteins have large number of ribosomes, made of RNA and proteins

Resolution

clarity of an image; the ability to distinguish 2 objects as 2 objects

secretory protiens

collagen, insulin, and idgestive enzyme of stomach and intestine

Lysosome

component of membrane-bound organelles that digest nutrients and cellular wastest (NOT IN PLANTS), "gargage unit"

nuceloulus

condensed region where ribosomes are formed

nucleus

contains nuclear envelope, chromatin, nucleolus, most of cells dna, controls cells activities by making messenger RNA (mRNA)

lysosome

digests nutrients and cellular wastes

chromatin

dna plus associated proteins

mitochondria in all cells and chloroplasts in plant cells

energy processing

both rough and smooth er

form vesifles that travel to other parts of the cell

cells wall, chloroplasts, and central vacuole

found only in plant cells

contracile vacuoles

help eliminate water from the protist

Magnification

increase in the apparent size of an object

Nuculeus and ribosomes

involved in genetic control of cells

endoplasmic reticulum, gogli apparatus, lysosomes, vacuoles, and peroxisomes

invovled in manufacture, distribution, and breakdown of molecules

smooth er

makes lipids, stores calcium ions, is a major function in lipid synthesis, produces enzumes important in the synthesis of lipids, oils, phospolipids, and steroids, other enzymes help process drugs, alcohol, and other harmful substances

nuclear envelope

membrane enclosing nucelus, protein lined pores, attatched to network of cellular membranes called the er

cytoskeleton

microtubule, microfilament, intermediate filament

golgi apparatus

molecular warehous and finishing factory for products manufactured by the er, products travel in transport vesicles from the er to golgi apparatus, one side functions as a recieving dock for the product and the other as a shipping dock, products are modified as they go from one side to the other and travel in vesicles to other sites, most frequent modification in golgi is addition of short chains of sugar molecules, modiefies proteins and lipids are tagged with phosphate groups or other small molecules

lysosomes and centrioles

not found in plant cells

light microscope

observing thin or transparent samples on slides

Bachteria and archaea

prokaryotic cells (smaller and simpler in structure)

cell wall

protects cell, provides structural support, gives shape to cell, cellulose major orjanic molecule in wall-provides protection of pathogens, contains plasmodesmata that allows cell to communicate

electron microscope

range of samples that can be opaque and of varying thicknesses

cis-face

recieving side

trans face

shipping side

Vesicle

small, membrane-bound sac that functions in storage and transport within a cell

cytoskeleton, plasman membrane, and cell wall

structural support, movement, and communication between cells

Nucleolus

structure in nucleus that is the site for ribosome synthesis

free ribosomes

suspended in cytoplasm, typically involeved in making proteins that function within the cytoplasm

Endosymbiont Theory

-Mitochondria and chloroplasts were formally small prokaryotes -began to live in larger cells

Endomembrane system (6)

-Nuclear envelope -Endoplasmic reticulum -Gogli Apparatus -Lysosomes -Vacuoles -Plasma Membrane within eukaryotic cells, some are physically connected and some are related by the transfer of membrane segments by tiny vesicles, work together in synthesis, storage and export of molecules

Mitochondria and Chloroplasts

-evolved by endosymbiosis -self-replicating (contain DNA and ribosomes) -DNA is similar to that found in prokayotes -found in cells of plants

chloroplasts

-have an outer membrane, an inner membrane, and membrane structures called thylakoids -thylakoids are stacked into grana - space inside thylakoid membrane is called thylakoid space -light harvesting reactions take place in the thylakoid membranes -synthesis of sugar takes place in fluid inside inner membrane, stroma -have their own geome which is contained on a single circular chromosome. -have own DNA and robosomes -autorophs (able to make their own food)

vacuoles

-have digestive functions -contain pigments -contain poisons that protect the plant

peroxizomes

metabilize waste

Microfilaments

-narrowest -function in cellular movement, 7nm diameter -made of 2 intertwined strands of gobular proteins called actin -known as actin filaments -provide rigidity and shape to the cell -can depolymerize (disassemble) and reform quickly, thus enabling a cell to change its shape and move

mitochondria

-organelles that carry out cellular respiration in eukaryotic cells -cellular respiration converts the chemical energy in foods to chemical energy in ATP -double membrane with narrow space between them -matrix containing mitochondrial DNA, ribosomes, and enzymes that are needed for cellular respiration -inner membrane contains fold called cristae which increase its surface area -intermembrane space -space inside membrane is called mitochondrial matrix -ATP synethesis takes place on the inner membrane

Actin

-powered by ATP -serves as track for the movement of a motor protein called myosin. This enables actin to engage in cellular events requiring motion, such as cell division in animal cells and cytoplasmic streaming, which is the circular movement of the cell cytoplasm in plant cells. Actin and myosin are plentiful in muscle cells. When your actin and myosin filaments slide past each other, your muscles contract.

Intermediate Filaments

-purely structural -bear tension to maintain the shape of the cell -anchor nucelus and other organelles in place -most diverse -keratin

cell theory

-schleiden, schawann, virchow -all living things are made of cells (unified cell theory) -cells are the basic unit of life -cells come from other cells (virchow)

proteins synthesized by rough er

-secretion outside of the cell -creating lysosomes -replacing proteins in the plasma membrane

Microtubules

-small hollow tubes -walls made of polymerized dimers of α-tubulin and β-tubulin, two globular proteins - widest components of the cytoskeleton. They - help the cell resist compression, provide a track along which vesicles move through the cell, and pull replicated chromosomes to opposite ends of a dividing -microtubules can dissolve and reform quickly -structural elements of flagella, cilia, and centrioles

How do nucleus and ribosomes work together to produce proteins?

In the nucleus, an mRNA copy of a gene is produced, which ribosomes use as instructions to synthesize a specific protein.

rough er

associated with ribosomes, makes secretory and membrane proteins, makes additional membranes for itself, proteins destined for secretions

bound ribosomes

attatched to er, associated with packaged proteins for export