Set 3 - Cell biology

Cell membrane

controls what enters and leaves the cell

Nucleus

stores genetic instructions

Ribosomes

manufacture proteins

Endoplasmic reticulum

helps synthesize and process molecules

Golgi apparatus

receives proteins and lipids from the ER, modifies them, sorts them, and packages them into vesicles for delivery

Mitochondria

generate much of the cell's ATP

Lysosomes

break down and recycle cellular material

DNA

contains instructions for producing proteins and regulating cellular activity

Chromosomes

Structures that organize DNA

Nuclear envelope

Double membrane surrounding the nucleus

Nuclear pores

Regulate movement of molecules between nucleus and cytoplasm

Chromatin

Complex mixture of DNA, RNA, and proteins that packages long DNA molecules into a compact, orderly shape inside the nucleus

Nucleolus

Region where components of ribosomes are produced and assembled

DNA mutation

Can alter proteins, disrupt cell regulation, and contribute to diseases like cancer

Codon

Three consecutive nucleotides in a DNA or mRNA molecule that encodes a specific amino acid or signals the start or termination of protein synthesis

Anticodon

Three consecutive nucleotides located on a transfer RNA (tRNA) molecule that binds to a complementary codon on a messenger RNA (mRNA) strand during protein synthesis

tRNA (transfer RNA)

small, specialized molecule that links codons on an mRNA molecule to the correct corresponding amino acids

mRNA

single-stranded molecule that carries genetic instructions from DNA to the ribosomes

Histones

Proteins found in the nucleus that provide structural support and packaging for DNA

Nucleosomes

The basic repeating unit of chromatin where DNA wraps twice around a core of eight histone proteins, resembling "beads on a string"

Chromatin fibers

Nucleosomes coil and fold into higher-order fibers

Ribosomes

Can be found:

• Free in the cytoplasm.

• Attached to the rough endoplasmic reticulum

Free Ribosomes

Synthesize proteins that function inside the cell (in the cytosol, nucleus, mitochondria, or peroxisomes)

Cytoplasm

the entire content of a cell inside the plasma membrane (excluding the nucleus in eukaryotic cells)

Cytosol

water-based, gel-like fluid that surrounds cell organelles

Rough ER Ribosomes

Synthesize proteins that are exported, secreted, or embedded (destined for the cell membrane, lysosomes, the Golgi apparatus, or outside the cell)

Peroxisomes

small, membrane-bound organelles that manage oxidation reactions, lipid processing, and cellular detoxification

Rough ER

• Synthesizing proteins destined for secretion or membranes.

• Helping proteins fold into their proper structures.

• Beginning protein modification and quality control.

Smooth ER

• Lipid and steroid synthesis.

• Detoxification of certain drugs and chemicals.

• Calcium storage and release.

Cis face

part of the Golgi apparatus that receives the transport vesicle from the ER

Trans face

part of the Golgi apparatus that ships the transport vesicle for delivery

Exocytosis

a form of active bulk transport in which a cell fuses internal membrane-bound vesicles with its outer plasma membrane to release large molecules, proteins, or waste products into the extracellular space

Mitochondria structure

• An outer membrane.

• An inner membrane, folded into structures called cristae.

• An internal space called the matrix.

Cristae

folded structures of the inner mitochondrial membrane which increase surface area for processes involved in ATP production

Matrix

Name for the internal space of the mitochondria

Lysosomes

contain digestive enzymes that break down:

• Damaged organelles.

• Cellular debris.

• Certain materials taken up by the cell.

Autophagy

process in which cells break down and recycle their own components.

Peroxisomes

contain enzymes involved in:

• Breaking down certain fatty acids.

• Metabolizing potentially harmful compounds.

• Producing and breaking down hydrogen peroxide.

Catalase

Enzyme that converts hydrogen peroxide into water and oxygen, contained in peroxisomes

Membrane proteins

transport substances, act as receptors, and help cells communicate

Cholesterol

helps regulate membrane fluidity and stability

Carbohydrate chains

help cells recognize and interact with one another

Fluid mosaic model

describes the call plasma membrane as a dynamic, two-dimensional liquid in which different types of molecules distributed throughout it can move laterally