bio unit 9

whats the bacteria structure

single celled ; prokaryotic (no nucleus)

function of bacteria plasmids

small circles of DNA with special genes - “extra genes”

function of bacteria ribosomes

to make proteins

function of bacteria cell membrane

thin lipid bilayer with proteins inside layer

function of bacteria cell wall

layer outside cell membrane, thick layer, protects the cell

function of bacteria capsule

outermost layers, prevents the cell from drying out, protects bacteria from a hosts immune system

function of bacteria pili

allows bacteria to attach to cell surfaces; can also be used to swap genetic material

function of bacteria flagella

tails used to move in water; spins like a propeller

what is binary fission?

how bacteria reproduce

steps of binary fission?

1. The cell copies its DNA (using enzymes)

2. Cell gets longer

3. The cell then divides into 2 identical cells

why do the bacteria need agar gel in the petri dish

its food for them (sugar)

why did we put the petri dishes into a warm incubator

so that they can grow, since they thrive in warm environments

what are some ways bacteria help us by living in/on our bodies?

Bacterial E.Coli helps us digest, produce necessary vitamins, absorb iron, defend against harmful microbes

what are some ways bacteria can make us sick by living in/on our bodies?

• can produce toxins in our digestive system

• can consume host cells/tissues

• cam grow out of control and consume healthy cells

what are antibiotics

medication used to treat bacterial infections (they kill/destroy the bacteria) NOT viral infections

what are antibiotic resistant bacteria

bacteria that has adapted to the exposure of harmful chemicals, allowing them to survive

what does a viruses capsid do

surrounds the genome

what does a viruses nucleic acid do

holds instructions for making more viruses

what does a viruses envelope do

allows viruses to sneak into the host cell

why do viruses take over host cells in order to reproduce? why cant they reproduce on non living surfaces in the environment?

because they’re non-living! they dont have a nucleus, so they can’t reproduce. Therefore, they have to take over a host cell in order to replicate themselves

steps of viral reproduction within a host cell

Step 1: Attachment

Step 2: entry

Step 3: transcription/translation

Step 4: assembly

Step 5: release

What is homeostasis?

the bodys process of maintaining a healthy range for a # of factors

what are WBC and what are some diff things they can do during an immune response?

They’re cells that fight infections. They can attack/destroy pathogens, make antibodies, and send signals to other immune cells

What is the prupose of signal molecules in the immune system

chemical molecules that carry the info to other cells; they travel through circulatory system

does positive feedback promote or inhibit the immune response

promote

how does a fever help our bodies fight bacteria or viruses

fevers make it harder for pathogens to survive and helps immune cells work faster

what is negative feedback

inhibits the change, brings things back to normal

explain the role of negative feedback in a healthy immune system

neg feedback stops the immune response after the infection is gone

what is an antigen?

substances that provoke an immune response

what are antibodies?

proteins made by WBC to help flg/tag specific pathogens

what is the purpose of vaccines and how do they work

vaccines give a harmless antigen so your body makes antibodies + memory cells

how can we use VEAR to explain how bacteria can become resistance to antibiotics

V- a bunch of bacteria, including a resistant variety

E- get bathed in antibiotics. Most of the normal bacteria die

A- the resistant bacteria multiply & become more common

R- eventually, the entire infection evolves into a resistant strain

what are viruses

very small - 1,000 times smaller than a human skin cell

virus structure

genome (RNA or DNA)

protein coat (called a capsid)

signal molecules

chemical molecules that carry the info to other cells

target cells

receive the information and respond

autoimmune disease

The immune system malfunctions, it mistakenly attacks healthy cells, tissues, and organs. Most last whole life