Biology

Preparing for my Biology Final Exam

Nucleus

Control center. Contains DNA

Mitochondria

Converts high-energy molecules into ATP. Site of cellular respiration

Rough Endoplasmic Reticulum

Primary site of protein creation in the cell, Contains Ribosomes

Ribosomes

Sites where proteins are made. Often attached to rough endoplasmic reticulum

Golgi Apparatus

Receives substances from ER and stores, modifies, and transports these substances

Vacuole

An organelle that stores food, cell products / excess fluids in animal cells. It maintains turgor pressure.

Lysosome (animals only)

Responsible for digestion & cellular recycling & waste breakdown.

Cell Wall (plants only)

Further stiff wall separating the tissue. Only present in plant cells.

Chloroplast (plants only)

Contain the pigments which collect light for photosynthesis (carbon dioxide & water react to produce glucose & oxygen)

Phloem

Transports sugars from the leaves to the rest of the plant.

Xylem (Sapwood)

Moves water/minerals from roots to leaves

Brownian Motion

The random movement of small particles often through water.

Passive Transport

Movement of material through diffusion/osmosis-no energy is used for this to occur.

Diffusion

Responsible for gas exchange between the spongy tissue & the palisades. Pressure from an area of high-low concentration.

Osmosis

Diffusion of water across a selectively permeable membrane.

Hypertonic

The concentration of solutes (particles) outside the cell is larger than inside the cell. Water will move out of the cell. Cell will shrink

Hypotonic

The concentration of solutes (particles) outside the cell is smaller than inside the cell. Water will move into the cell. Cell will swell

Transpiration

The loss of water from plants by evaporation through stomata

Turgor Pressure

Water pressure inside a plant cell pushes against the rigid cell wall causing turgor pressure

Micelle

When phospholipids are placed in water, they form small, single-layered spheres. They transport fats.

Liposome

Contains a double-layer of phospholipids and can trap water inside.

Fluid Mosaic Model

Cell membrane is not rigid like a wall but is flexible. Made up of many different parts; phosphates, lipids, proteins, etc.

Phospholipids

Primary component of a cell membrane

Channel Proteins

Doors allowing passage in and out of the cell (facilitated diffusion)

Carrier Proteins

Attach to larger particles and change shape to help move particle past the membrane. (facilitated diffusion)

Ion Transport Protein

Use energy to move charged particles against their concentration gradient.

Active transport

Cell uses energy to move transport against the concentration gradient

Vesicle

Small liposomes created by E.R to transport proteins throughout the cell.

Endocytosis

A cell can form a new vesicle by collapsing its membrane around matter in the environment to take it in.

Exocytosis

When the vesicle fuses with cell membrane to release contents into the extracellular fluid. Allows for plants to move large numbers of proteins out of a cell at once

Cohesion and Adhesion of water

The property for water to stick to itself is called cohesion. The ability for water to stick to other substances is called adhesion.

Epidermis and Cuticle

Outermost layer of cell. Cuticle is the hardened layer along the top. Protect plants from pathogens & prevents excess water loss during transpiration.

Palisade Tissue

Primary site for photosynthesis. Top of leaf. Contain chloroplasts

Spongy Tissue

Stores sugar. Under palisade tissue. Gas exchange

Stoma & Guard Cells

Guard Cells, cells on the underside of leaves, form tiny pores called stomata which allow for gas exchange.

Lenticels

Gas exchange can also take place through the stem/trunk of a plant through openings called lenticels.

Auxin

Chemical substance that promotes the elongation of a plant

Phototropism

The growth of a shoot toward light is called positive phototropism. Negative phototropism occurs in the root (auxin inhibits growth) when the root grows away from the light.

Gravitropism

When the stem grows against the force of gravity (upwards), this is known as a negative gravitropism. When a root grows in the direction of the force of gravity (downwards), this is known as a positive gravitropism.

Square-Cube Law

If you double the height of a cube the surface area increases by 4x and the volume increases by 8x.

Root Pressure

Active push of water and minerals upward through the roots into the stem