Bio 151

Study flashcards for chapter 1

What are prokaryotes?

Bacteria that is

\-Unicellular

\-No interior compartments

\-Cell membrane

\-Cell wall

\- Some are photosynthetic

\-No true organelles

What do viruses depend on cells for?

\-Metabolism (both catabolic and anabolic processes) Reproduction -Transcription and Translation

What are Eukaryotes?

Internal membrane bound organelles • Some have cell walls (fungi, plant) some don’t (such as animal cells) • All have membranes • Nucleus • Some are photosynthetic

What is the function of the Nucleus?

Stores DNA to transcribe it into RNA

What is the function of the Plasma membrane?

Separate the inside of the cell from the outside of the cell made from \n proteins, carbohydrates, and phospholipids – controls access to the \n cell.

What is the function of the Chloroplast?

Produces sugars from light energy and CO2 and produces O2

What is the function of Mitochondria?

Converts pyruvate into ATP, CO2, and makes small carbon molecules for the rest of the cell.

Are all organisms made of cells or have a single cell?

All living things are made up of cells, but they can have different numbers of cells. Organisms can be unicellular, like bacteria and protozoa, with just one cell that does everything. Or they can be multicellular, like plants, animals, and fungi

What is the plasma membrane made of?

 Lipids, proteins, and carbohydrates. 

Do viruses have dna?

Yes, but not all viruses have DNA. Some viruses have RNA (ribonucleic acid) as their genetic material instead. 

Are viruses unicellular?

No. Viruses require a host cell to replicate and carry out their life cycle. Once inside a host cell, viruses hijack the cellular machinery to produce more viruses. 

What does it mean to be unicellular?

Unicellular organisms are complete, self-contained units of life that can carry out all necessary functions within a single cell. They are capable of performing essential processes such as obtaining nutrients, metabolizing, reproducing, and responding to their environment.

What are carbohydrates?

Macromolecules that give energy through glucose

What are the three subtypes of carbohydrates and their definition

Monosaccharides: Simple sugars like glucose, galactose, fructose. Ratio of carbon :3-6

Disaccharides: Form of two monosaccharides. When two monosaccharides form a dehydration reaction (removal of water molecule)

Polysaccharides: Complex carbohydrates made up of multiple monosaccharides

What are examples of disaccharides?

Sucrose (Glucose+ Fructose), Lactose (Glucose + Galactose) Maltose (Glucose +glucose)

How are disaccharides broken into monosaccharides?

Through Hydrolysis: A chemical reaction where bonds are broken by adding water. Water is split by hydrogen (H+) and hydroxide ions (OH-) which breaks bonds between molecules. Used to break down complex molecules into smaller units like disaccharides into monosaccharides or proteins into amino acids

What are polysaccharides?

A long chain of monosaccharides. Examples: Starches, glycogen, cellulose and chitin.

What are Lipids?

Nonpolar molecules that are hydrophobic. Cells store energy in form of lipids called fats.

What are phospholipids and function?

Composed of fatty acid chains attached to glycerol or a similar backbone. Has both hydrophobic and hydrophilic regions. The phosphate group can face outside and the fatty acids stay inside. It is a bilayer that makes up cell membranes.

Are all eukaryotic cells heterotrophic?

No, they can be heterotrophic and autotrophic

What is autotrophic?

Consume food from themselves to gain energy.

What is heterotrophic?

Consume food from other products to get energy

What is the difference between anabolic and catabolic reactions?

Anabolic reactions use energy to build from complex molecules such as amino acids becoming proteins. Catabolic reactions break complex molecules down into simpler ones which releases chemical energy

What is an example of Catabolic reaction?

Glycolysis, food digestion.

What is the primary biomolecule for hereditary?

Nucleotides since they make up DNA.

What is the function of Primary Structure for Protein Folding

Determines the specific sequence of amino acids in protein which determines its function and interactions with other molecules

What is the function of Secondary Structure for Protein Folding?

It includes alpha helices and beta sheets, provides stability and rigidity for protein, and allows it to maintain shape and interact with specific molecules

What is the function of Tertiary structure for Protein Folding?

Responsible for three three-dimensional shapes of protein and determines proteins’ function by enabling specific binding sites, catalytic activity and interactions with other molecules

What is the function of Quaternary Structure?

Arranges multiple protein subunits such as hemoglobin which carries oxygen.

What is the function of the Lactase in E. Coli?

The lactase binds to the regulatory protein repressor by the alactose. It creates a conformational change preventing it from binding to the operator so RNA polymerase is able to bind to the promoter to initiate transcription

what is a trans fatty acid

a trans fatty acid is straight with no kink so less fluid

what is a cis fatty acid

causes a kink and changes direction which makes it more fluid

What is Lacl code for

The repressor

what’s the difference between heterochromatin vs euchromatin

Heterochromatin is highly condensed, gene-poor, and transcriptionally silent. Euchromatin is less condensed, gene-rich, and more easily transcribed

what are nucelotides

section of DNA that is wrapped around core of protein

What does the lac repressor do when there is no lactose present?

Binds to the operator preventing RNA polymerase from attaching to the promoter

what happens when there is lactose present?

Lactose binds to the lacl repressor which creates an confrontational change to the shape which causes rna polymerase to then bind to promoter and transcription occuring

When is transcription at its highest?

When there is low glucose and high lactose.

Describe the Central Dogma of Biology

DNA-MRNA-PROTIEN

What is transcription?

Where genetic information stored in DNA is used to synthesize RNA

What is translation

going from mRNA to protein

what are protiens made of

amino acids

what are sterols

class of lipids(fats)

what are polypeptides?

consist of a chain of amino acids linked by peptide bonds and are building blocks of protiens

what are the building blocks of protien

polypeptides

what does cholesterol do in terms of membrane fluidity

acts as a buffer by preventing fatty acid chains of phospholipids from packing too closely together which helps regulate the membrane at different temperatures

What increases membrane fluidity

shorter chains or unsaturated fats with double bonds increase membrane fluidity. The double bonds introduces kinks to the membrane which prevents from packing closer.

What decreases membrane fluidity

Saturated fatty acids since they have straight chains that can pack tightly, making the membrane less fluid

What is passive diffusion

From high to low, carbon and water molecules and need to be nonpolar molecules

What is facilitated diffusion

From high to low and needs protein to go through a protein gradient, selective since it needs specific protein gradients.

What is active transport

Low to high and need energy to go through transport as it goes against the gradient. Uses atp to go through gradient

What is secondary active transport

Uses pumps and energy from both charged molecules to go move against gradient. Such as using Na+ and K to move against gradient to form energy

 Are Transcription factors (activators and repressors) and RNA polymerase (enzyme) proteins?

Yes

Can Epigenetic changes alter the base pairs? Why or why not?

No, they are chemical alternations to the DNA

What is DNA methylation

Addition of methyl groups in the cytosine residue, involved in gene splicing

What is RNA splicing?

removal of introns(non-coding sequence) and join exons(coding sequence) in pre mRNA to create mature mRNA. Splicesomes remove the introns

What is histone methylation

Tightens DNA structure and decreases transcription

what is histone Acetylation

This weakening of the interaction allows the DNA to unwind or loosen from the histones and increases transcription

How are nucleotides held together?

phosphodiester bonds

How are amino acids held together to become a polypeptide chain?

peptide bonds

What are peptide and phosphodiester bonds classified as?

covalent bonds