Cells Flashcards
What are the most abundant and versatile macromolecules?
Proteins
What is the structure of an amino acid?
It has an amino group on one end and a carbonyl group on the other as well as a R group
What is an R group?
A side chain attached to amino acids which determine its chemical and physical properties
What links amino acids in proteins together? What does this bond form between?
Peptide bonds, forms between the carbonyl group of one amino acid and the amino group of another
What are the carbonyl and amino ends of an amino acid sequence called?
N-terminus and C-terminus
What is the primary structure of a protein? What bonds are used?
Amino acid sequence, uses peptide bonds
What are the types of secondary structures? What type of bond is used?
Alpha-helix and beta-pleated sheet, hydrogen bonds
Do proteins need to contain only one type of secondary structure?
No it can be a mix of both
What is tertiary structure? What bonds are used?
Folding due to R-group interactions, can be ionic, disulfide, hydrogen, or van der waals bonds
What determines the type of bond in tertiary structure?
The type of R-group
What is quaternary structure?
Structure involving more than one polypeptide
A protein made up of more than one polypeptide contains which structure(s)?
Primary, secondary, tertiary, and quaternary
What helps make sure that proteins are properly folded?
Chaperone proteins which ensure they fold properly and other proteins which eliminate improperly folded proteins
What are some of the primary functions of carbohydrates in cells?
Energy storage, cell identity, structure, and building blocks
Lipid structure is diverse but they are usually?
Hydrophobic/non-polar
What is the basic unit of a nucleic acid called?
Nucleotide
What are nucleotides composed of?
A nitrogenous base, a pentose sugar, and a phosphate group
What are the similarities and differences between DNA and RNA?
- both made of nucleotides
- both contain 4 nitrogenous bases
- DNA has thymine and rna has uracil
- dna is double stranded rna is single stranded
- dna can self replicate rna cannot
What is the flow of information in cells?
DNA codes for RNA which codes for proteins
What is transcription? What facilitates this process?
Turning DNA into RNA, rna polyermerase
What is translation? What facilitates this process?
Turning RNA into proteins, ribosomes
What are three things that are true of all cells concerning energy and metabolism?
- All cells need source of carbon and energy
- All cells use energy to build macromolecules and carry out processes of life
- All cells use atp as the major energy carrier
What is the difference between autotrophs and heterotrophs?
Autotrophs make their own energy and heterotrophs get it from other organisms
What is the difference between phototrophs, chemoorganotrophs, and chemolithotrophs?
Phototrophs get energy from sunlight, chemoorganotrophs get energy from organic molecules, and chemolithotrophs get energy from inorganic kolecules
Which domain of organisms have more diversity in how they obtain energy?
Prokaryotes
What are some common structural features that prokaryotic cells share?
- no nucleus
- ribosomes
- cytoplasm
- cell membrane
- cell wall
- glycocalyx
- flagella/pili
What is true about bacterial DNA?
Most have a single, circular DNA molecule and it is contained in the nucleoid
What are plasmids?
Extra-chromosomal pieces of DNA that carry non-essential genes
What is true of plasmid structure and function?
Small circular DNA molecules, extra genes that can have beneficial or detrimental affects, replicate independently of chromosomal DNA, and bacteria may lose plasmids when they replicate
What protein is involved in binary fission? What is its purpose?
FtsZ, forms a ring in center of bacteria and pinches cytoplasm until it seperates
What protein is used in rod shaped cells specifically? What is the purpose?
MreB proteins, maintains the rod shape
What are ribosomes?
Macromolecular machines for protein synthesis made up of protein and RNA
What is the cytoskeleton?
Proteins involved in support, shape, and cell divison
What are the functions of the bacterial cell membrane?
Boundary of the cell, metabolism, photosynthetic bacteria also often have internal membrane which derives from the plasma membrane
Bacteria cell walls can be? What is the difference?
Gram positive bacteria (single, thick peptidoglycan layer) or gram negative bacteria (thin peptidoglycan layer surrounded by outer membrane)
Which type of cell wall is more susceptible to an antibiotic which targets the cell wall? Why?
Gram positive cell wall, not protected by outer membrane
What can weakening the cell wall lead to? What can cause this?
Cell rupture and death, antibiotics that target peptidoglycan synthesis and lysozyme
What is the glycocalyx?
A structure outside the cell wall of some bacteria, sometimes called capsule or slime layer
What is the purpose of the glycocalyx?
Protects bacteria from extreme temperatures, desiccation, antibiotics, viruses, antibodies
What are flagella?
Allows for movement
What are fimbriae?
Short, hair like structure that is used for attaching to surfaces or other cells, not used for mobility
What are pili?
Short structure used to make initial contact to bring bacteria together to transfer genetic material (conjugation)
How are archaea similar to bacteria?
Many are found in extreme environments, diverse metabolisms, prokaryotes, nucleoid, circular chromosome, ribosomes, cytoskeleton, most have cell walls, some have glycocalyx, flagella, and fimbria like structures
What part of archaea is more similar to eukaryotic cells than bacteria?
The information system (ribosomal structure, and the aspects of translation and transcription)
How are archaea structurally different from bacteria and eukaryotes?
- Have a unique flagella, cell wall, glycocalyx, fimbria-like structures, cytoskeleton, membrane lipids
What are the major differences between eukaryotic cells and bacteria/archaea?
Larger than prokaryotes, distinct nucleus surrounded by nuclear envelope, membrane bound organelles (endomembrane system)
What are similarities and differences between plant and animal cells?
- both have nucleus, cell membrane, mitochondria, ER, ribosomes, golgi etc
- plant cells have chloroplasts and a cell wall and animal cells don’t
- animal cells have lysosomes and centrioles and plant cells don’t
- in plant cells vacuoles are large, there is only one, and helps maintain water balance and in animal cells there are many small vacuoles and help store waste