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UA / Biological Sciences / BSC 108 / When do antibiotics discover?

When do antibiotics discover?

When do antibiotics discover?

Description

School: University of Alabama - Tuscaloosa
Department: Biological Sciences
Course: Intro Biology Non Major I
Professor: Christine yates
Term: Spring 2017
Tags:
Cost: 25
Name: BSC 108 Ch. 4 Notes
Description: This is ALL of chapter 4 notes. So, what that means is this is several lectures in one document BUT its all of the chapter 4. (Mrs. Yates Class)
Uploaded: 02/08/2017
4 Pages 110 Views 1 Unlocks
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BSC 108 Ch. 4


When do antibiotics discover?



A TOUR OF THE CELL

DRUGS THAT TARGET BACTERIAL CELLS

Antibiotics were first isolated from mold in 1928

the widespread use of antibiotics drastically decreased deaths from bacterial infections most antibiotics kill bacteria while minimally harming the human host by binding to structures found only on bacterial cells

some antibiotics bind to the bacterial ribosome, leaving human ribosomes unaffected other antibiotics target enzymes found only in the bacterial cells

MICROSCOPES AS WINDOWS ON THE WORLD OF CELLS

Light microscopes can be used to explore the structures and functions of cells

when scientists examine a specimen on a microscope slide

light passes through the specimen

lenses enlarge, or magnify, the image


What is the use of light microscopes?



2 factors that determine the quality of microscopy

magnification is an increase in the specimen's apparent size

resolving power is the ability of an optical instrument to show 2 objects as separate cells were first described in 1665 by Robert Hooke

The accumulation of scientific evidence led to the cell theory

all living things are composed of cells

all cells come from other cells

The light microscope is used by many centrists

light passes through the specimen

lenses enlarge, or magnify, the image

The electron microscope (EM) uses a beam of electrons

results in better resolving power than the light microscope

2 kinds of electron microscopes reveal different parts of cells


What are the factors that determine the quality of microscopy?



Don't forget about the age old question of What are the goals of the southern plantation owner class?

scanning electron microscopes examine cell surfaces

transmission electron microscopes (TEM) are useful for internal details of cells

FEATURES COMMON TO ALL CELLS

All cells have a plasma membrane-phosolipid bilayer-selective barrier

all cells have a cytosol, or cytoplasm-the area within the membrane not including organelles all cells have at least 1 chromosome-containing DNA

all cells have ribosomes-sites of protein synthesis

THE TWO MAJOR CATEGORIES OF CELLS If you want to learn more check out Is “diets high in calcium promote strong bones” a nutrient, health, or structure-function claim?

the countless cells on earth fall into 2 categories

prokaryotic cells--bacteria and archaea

eukaryotic cells-plants, fungi, and animals

all cells have several basic functions

they are all bound by a thin plasma membrane

all cells have DNA and ribosomes

Prokaryotic and Eukaryotic cells have important differences

prokaryotic cells are older than eukaryotic cells

prokaryotes appeared about 3.5 billion years ago; eukaryotes about 2.1 billion years ago PROKARYOTES

Are smaller than eukaryotic cells

lack internal structures surrounded by membranes

lack a nucleus

have a rigid cell wall

PROKARYOTIC CELL WALLS

prokaryotes have cell walls that are unique

bacterial walls are made of peptidoglycan

a target for antibiotics

EUKARYOTIC CELL WALLS If you want to learn more check out Where are most adolescents living today?

plant cells have cell walls outside of their membranes We also discuss several other topics like What are the major factors of social change?

protect the cells

maintain their shape

keeps the cells from absorbing too much water

made mostly of cellulose-a carbohydrate

animal cells have extracellular matrix

helps hold cells together in tissues and protects and supports them

STRUCTURE AND FUNCTION OF THE NUCLEUS

The nucleus is bordered by a double membrane called the nuclear envelope

pores in the envelope allow materials to move between the nucleus and the cytoplasm the nucleus contains a nucleolus where ribosomes are made

stored in the nucleus are long DNA molecules and associated proteins that form fibers called chromatin each long chromatin fiber constitutes one chromosome

the number of chromosomes in a cell depends on the species We also discuss several other topics like What is it called when you can feel emotions?
If you want to learn more check out Does the total energy of a system remain constant?

RIBOSOMES

ribosomes are responsible for protein synthesis

ribosome components are made in the nucleolus but assembled in the cytoplasm

ribosomes may assemble proteins

suspended in the fluid of the cytoplasm or

attached to the outside of an organelle called the endoplasmic reticulum

DNA directs protein production by transferring its coded information into messenger RNA (mRNA) Messenger RNA exits the nucleus through pores in the nuclear envelope

a ribosome moves along the mRNA translating the genetic message into a protein with a specific amino acid sequence

THE ENDOMEMBRANE SYSTEM: MANUFACTURING AND DISTRIBUTING CELLULAR PRODUCTS

Several membranous organelles belong to the endomembrane system

endoplasmic reticulum

golgi apparatus

lysosomes

vacuoles

nuclear envelope

The endoplasmic reticulum (ER)

modifies an enormous variety of proteins that are first made on ribosomes

is composed of smooth and rough ER

ROUGH ER

the rough appearance of parts of the ER is due to ribosomes that stud the outside of the ER membrane the functions of the rough ER include the modification of

membrane proteins

secretory proteins

and the production of new membrane

after the rough ER synthesizes a molecule, it packages the molecule into transport vesicles SMOOTH ER

The smooth ER lacks surface ribosomes

It produces lipids, including steroids

It also is home to enzymes that detoxify foreign molecules

Ex. Drugs

 As liver cells are exposed to a drug the amounts of smooth ER increases  means the body will require more amounts of that drug to achieve the same effect

THE GOLGI APPARATUS

Works in partnership with the ER

Refines, stores, and distributes the chemical products of cells

LYSOSOMES

A lysosome is a sac of digestive enzymes found in animal cells

Enzymes in a lysosome can break down large molecules such as

proteins

polysaccharides

fats

nucleic acids

Lysosomes have several types of digestive functions

Many cells engulf nutrients in tiny cytoplasmic sacs called food vacuoles

these food vacuoles fuse with lysosomes, exposing food to enzymes to digest the food Small molecules from digestion leave the lysosome and nourish the cell

can also destroy harmful bacteria and break down damaged organelles

LYSOSOMES AND DISEASE

Several serious inherited disorders are the result of malfunctioning lysosomes VACUOLES

Vacuoles are membranous sacs that bud from the ER, golgi, plasma membrane EX: contractile vacuoles of protists

Contractile vacuoles of proteins pump out excess water in the cell

central vacuoles of plants

store nutrients

absorb water

may contain pigments or poisons

CHLOROPLASTS AND MITOCHONDRIA ENERGY CONVERSION

Cells require a constant energy supply to perform the work of life.

CHLOROPLASTS

Most of the living world runs on the energy provided by photosynthesis

photosynthesis is the conversion of light energy from the sun to the chemical energy of sugar chloroplasts are the organelles that perform photosynthesis

chloroplasts have 3 major compartments

the space between the 2 membranes

the stroma, a thick fluid within the chloroplast

the space within grans, the structures that trap light energy and convert it to chemical energy MITOCHONDRIA

Mitochondria are the sites of cellular respiration, which produce ATP from the energy of food molecules Mitochondria are found in almost all eukaryotic cells

an envelope of 2 membranes encloses the mitochondrion. These consist of

an other smooth membrane

an inner membrane that has numerous infoldings called cristae

Mitochondria and chloroplasts contain their own DNA, which encodes some of their proteins This DNA is evidence that mitochondria and chloroplasts evolved from free-living prokaryotes in the distant past

THE CYTOSKELETON: CELL SHAPE AND MOVEMENT

the cytoskeleton is a network of fibers extending throughout the cytoplasm

the cytoskeleton

provides mechanical support to the cell

maintains its shape

The cytoskeleton contains several types of fibers made from different proteins

Microtubles

 are straight and hollow

 guide the movement of organelles and chromosomes

Intermediate filaments and microfilaments are thinner and solid

The cytoskeleton is dynamic

CILIA AND FLAGELLA

motile appendages

flagella propel the cell in a whip-like motion

cilia move in a coordinated back and forth motion

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