AP BIOLOGY | Unit 2: Cells

nuclues

• contains DNA

• controls cell

nucleolis

• synthesizing ribosomal RNA (rRNA) and assembling ribosomal subunits needed for protein synthesis

rough endoplasmic reticulum

• ribosomes attached

• produces proteins that will leave the cell

• primarily responsible for protein synthesis, folding, and transport, especially for proteins destined for export or the cell membrane.

smooth endoplasmic reticulum

• no ribosomes attached

• variety of functions

• lipid synthesis, steroid production, detoxification, and calcium storage. 

  
  

golgi apparatus

• processes and packages proteins

• close to membrane

lysosome

• digestive enzymes to break down materials

mitochondria

• produce ATP by cellular respiration

ribosomes

• produces proteins

• free floating

chloroplasts

• produces glucose through photosynthesis

vacuoles

• fluid storage

• plants have bigger ones than animal cells

• food vacuole: digests ingested particles, containing enzymes to break down food for nutrients

• contractile vacuole: expels excess water from the cell to maintain osmotic balance and prevent rupture

• central vacuole: stores water, nutrients, and waste in plant cells, maintains turgor pressure for structural support, and can act in digestion

vesicles

• transport materials inside cell

microtubules

• moving chromosomes during cell division

centrioles

• anchor points for microtubules during cell division

cytoskeleton

• gives structure and support to cell

• made of protein fibers

peroxisomes

• carry out oxidation reactions, breaking down fatty acids and detoxifying harmful substances like hydrogen peroxide

cillia

• hair-like structure for movement

• small, many

flagella

• whip-like structure for movement

• usually larger, one present

plasma membrane

• outer layer/border of cell

cytoplasm

• inside jelly-like filling

extra cellular matrix (ECM)

• acts like an internal scaffolding for cells, providing support, structure, and a place for them to attach to

• a complex network of proteins, carbohydrates, and other molecules that surrounds and supports cells in tissues and organs.

• NOT in the cell, surrounds cells

What do all cells include?

• a plasma membrane

• cytoplasm (a gel-like substance)

• ribosomes (to build proteins),

• genetic material (DNA)

Relationship

DNA and RNA are types of nucleic acids. Nucleic acids are long-chain polymers that carry the genetic information for all living organisms. (DNA and RNA are both made up of smaller units called nucleotides)

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The individual building blocks of nucleic acids are called nucleotides. Each nucleotide is composed of three parts: 

• A five-carbon sugar

• A phosphate group

• A nitrogenous base (A, T, G, or C in DNA, and A, U, G, or C in RNA) .

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A, T, G, and C are specific nitrogenous bases. In DNA, adenine (A), guanine (G), cytosine (C), and thymine (T) are the four bases. In RNA, uracil (U) replaces thymine. 

Amino acids

Amino acids, the building blocks of proteins, are composed of a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a side chain that varies for each amino acid. 

Which Nitrogenous bases are Purimes and which are Pyrimidines?

• Purine: A and G

• Pyrimidines: C T U

Cytoskeleton and ECM differences

• The cytoskeleton is an internal protein network within a cell that provides structural support and enables movement, while the extracellular matrix (ECM) is an external network of macromolecules that provides support to tissues and coordinates cellular behaviors like adhesion and migration

• the cytoskeleton is an internal protein network that provides cell structure, while the ECM is an external network of proteins and other molecules that supports cells and tissues.