Bacteria and Cynobacteria Flashcards
What are the main characteristics of a prokaryote?
- Single Celled
- No nucleus
- Single-stranded DNA
- No membrane-bound organelles
What are the six ways we classify bacteria?
a. Shape
b. locomotion
c. nutrition
d. colony appearance
e. pigmentation
f. structure of the cell wall - gram stain (positive or negative)
What are the 3 common shapes of bacteria?
- Bacilli (spherical)
- Cocci (circular)
- Spirilli (spiral)
What do bacteria use for locomotion?
Bacteria have flagella (singular flagellum). They could have 1 or more than 1. They also have pili which fall under 2 general categories: fimbriae and sex pilus (long)
What are organisms that only need carbon dioxide or related compounds called?
Autotrophs
Photoautotrophs
Organisms that can turn light into energy, they’re photosynthetic.
What do photoautotrophs need other than sunlight for photosynthesis to occur?
CO2 and H2O
What are the products of photosynthesis?
Glucose and Oxygen
Chemotrophs
Organisms that obtain energy from chemicals
What uses organic compounds for their energy source and carbon source?
Chemoheterotroph
What is a Heterotroph?
An organism that requires at least one organic nutrient to make another organic compound.
Obligate aerobic/anaerobic bacteria
Uses oxygen for cellular respiration, and can’t grow without it.
Poisoned by oxygen and may use fermentation or anaerobic respiration in which substances such as nitrates are used to produce energy.
Facultative anaerobic bacteria
Uses oxygen if present, but can live in an anaerobic environment.
What is a colony?
A visible cluster of bacteria growing on the surface of an agar plate, formed from a single bacterium. It’s formed by binary fission.
Gram Stain
Gram-positive bacteria stain purple, while gram-negative stain pink. The different stains are due to the structure of the bacterium’s cell wall. Gram-positive organisms have a higher peptidoglycan content, while negatives have higher lipid content.